Real Submarine Technology & History Q&A

[TorpX]

Hello everybody. I've been playing SH 4 for a little while, but am new to the forum. This is a great place and I always learn something here.

First, I would like to thank DaveyJ, and all the other Vets, not only for their service, but for the infornation and insights they provide.:salute:


Second, I have a few questions about the S-boats.
Patrol Endurance. How long could they remain at sea? Apart from fuel considerations how much food could they carry?
Battery Capacity. How far could they go while submerged? In 1941, were their batteries degraded or had they recieved refits before wartime deployment?
Surface Speed. How fast could they go in heavy seas? In SH4 they can plow through rough seas with little problem, but it seems to me this is a game flaw.
Thanks in advance.

[Arael]

On the subject of the S-Boats, what is that funny little ball that's sticking up out of the deck near the bow?

[Stormende]

I have question on following text from U.S.S. BAYA (SS-318) FOURTH WAR PATROL REPORT27 April 1945 at 0235:
"APR contact on 305 mcs., 200 TRF, strength 5. This contact was followed by jamming which effectively blacked both united of APR and completely blacked SD."

Could someone explain what are APR, mcs, TRF and this "strength 5"? Also what kind of jamming gear Japanese would be using?

EDIT: Okay I missed section where APR was mentioned to be somekind of radio, my bad. Would still like to hear more about it.

Thanks!
Tim


305 Mega Cycles (now MHz) APR/SPR (Shipboard Radar Receiver), meaning the radar picked up a contact on 305 Mega Cycles, then the RBS detected an emission on 200 Kilo Cycles (kcs), I believe this was the so called jamming signal which had a strenght of 5 (bars) as it was already explained by Platapus.

... RCM receivers were very effective in detecting enemy radars at ranges far beyond the range of our own radars. This is because we could detect their strong transmitter pulses at ranges where echoes were too faint to be received. Good RCM operators could tell when snoopers were searching, when they had discovered us, and when they were commencing a run on us. RCM transmitters of fairly low power (10-100 watts) could thoroughly jam the enemy’s radar receiver, since echoes bounced off of us would have only milliwatts of power. (sic)

Check these sites for more detailed info:

http://www.ka8vit.com/subops/default.htm

http://www.history.navy.mil/books/opnav20-p1000/index.html

http://www.smecc.org/mcmahon's_radars!.htm


:salute:

[rein1705]

On the subject of the S-Boats, what is that funny little ball that's sticking up out of the deck near the bow?

That my friend is the sonar sound head.

[Elektroniikka-Asentaja]

This is very simple question that may have been asked before but I'm lazy and didn't want to search whole thread.. And now someone can feel useful when he tells me:

Was it possible to use diesel engines in WWII submarines when they were submerged? As we all know it is not an option in SH4 and I'm not very good in submarine history (Although reading trough this thread I bet that I'd know more about submarines than anyone in my town..)

I just wondered that because how would they pump out exhaust gases? And if they had a hole for that in the boat how didn't the water come in? :hmmm:

(Also isn't CO2 lighter than air right? Why didn't they pump exhaust gases to air tanks if they were short on compressed air if those gases would have worked even better? :D Yea, perhaps I'll let submarine building to engineers who know what to do :har:)

Happy hunting everyone! :salute:

PS question: Just came in my mind from that salute smiley, did submarine captain really do that much work as we do in SH4 or did those lieutenants and petty officers etc. do their own choices for example in shooting torpedos if and when captain was sleeping or something?
...yes I know that captains weren't sleeping during convoy/Task Force attacks but anyway...

[Gargamel]

Without a snorkel (http://en.wikipedia.org/wiki/Schnorkel), no, subs could not run their diesel's underwater. The engines would quickly suck all the breathable air from the boat, and replace it with toxic exhaust.

With the addition of a schnorkel, subs could run their diesels while submerged, but only very shallow. The pipe was much larger than a periscope, and therefore easier to detect, so they couldn't use it when approaching ships to attack.

CO2 is heavier than Oxygen and Nitrogen, which are the main components of 'air' (21% and 76% respectively), while CO2 is a component of 'air' (about 2%). So yes, CO2 would settle lower in the boat, but it wouldn't take long for it to fill up. Using compressed air to vent the boat worked a little, but you didn't want to waste the compressed air, as you needed it for driving the boat. Also, in order to vent the air, and it depended on the system they used, you may have to over pressurize the boat to force the air out, and then you'd compress the sailors too. You'd then end up with the same problems divers face with decompression sickness. That could be avoided with a negative pressure pump, sucking the air out, but it would cause much discomfort if the guy running the valves varied the pressure slightly (Think about driving down a big hill quickly, or in an airplane, having to equalize your ears).

I may be wrong here, as it's just supposition on my part.

[Gargamel]

On the subject of the S-Boats, what is that funny little ball that's sticking up out of the deck near the bow?

I have noticed that on a lot of pics of British boats from the 80's and 90's (http://www.subsim.com/radioroom/showthread.php?t=178973) too. I too am curious.

[ReallyDedPoet]

I have spent the last week and a half revising the Wikipedia page on the Gato class submarines. The original was incomplete, misleading, and in some cases completely wrong. I think it will stand the test now. Take a look when you have the chance:

http://en.wikipedia.org/wiki/Gato_class_submarine

Enjoy!

Just seeing this now as well. Very nice :up:

[Platapus]

Another lubber of land question.

I am rereading Beach's Run Silent Run Deep. If anyone has not read it, I highly recommend it. Beach was a talented writer. I found myself slightly out of breath just reading the first two chapters.

Anyway, about 2/3rds though the book, Beach makes a comment that the Negative Tank, unlike the other tanks is vented directly into the submarine. In the story he relates a circumstance where during an emergency dive, the negative tank was not blown when it should have been and when they blew it at a deeper depth it caused discomfort in the submarine.

Beach is pretty accurate in his books. But is this true?

Negative Tank vents only into the Submarine?

Why? is this to help conceal the submarine during the dive?

It is my understanding/(misunderstanding?) that during a normal dive, the negative tank is flooded, but when the submarine is on the way down, it is blown at a relatively shallow depth. The purpose of the negative tank is to give the submarine that extra kick to get under faster.

By venting the Negative tank into the submarine, there would not be a big sub fart of air telling the enemy where the sub is.

Is this correct or do I need to go back to lubbing land again?

[TorpX]

I could be wrong but I was under the impression that the negative tank was only flooded when they wanted to go deep fast (i.e. an emergency).

As far as the venting is concerned, I don't know. Your guess seems reasonable though.

I was wrong, the negative tank was routinely used.

This was posted in another thread by Takao: http://www.history.navy.mil/library/online/ss-doc-2.htm

Very interesting.

[LukeFF]

Second, I have a few questions about the S-boats.

Patrol Endurance. How long could they remain at sea? Apart from fuel considerations how much food could they carry?

Offhand I don't recall, other than that, according to 1939 data, the max range was about 10,000 miles at 8 knots surfaced. Of course, the fuel tanks in these boats were known to constantly leak, so that number could vary significantly.

Battery Capacity. How far could they go while submerged? In 1941, were their batteries degraded or had they recieved refits before wartime deployment?

There was not a lot of funding available for S boats in the 1930s, so their first modernization refits/overhauls typically did not occur until late 1942/early 1943. So yes, in general, the equipment was very old and in need of an upgrade. Submerged speed/range at the outbreak of war in 1939 was 100 miles at 5 knots. Max submerged speed for S-18s was 9 knots and 9.5 for S-42s (again, 1939 data).

Surface Speed. How fast could they go in heavy seas? In SH4 they can plow through rough seas with little problem, but it seems to me this is a game flaw.
Max speed was 13 knots for the S-18 and 12.5 for the S-42. In heavy seas, no doubt it was noticeably less. The S boats were not known for their sea keeping abilities.

[Kruger]

I've read the entire thread today, amazing how much information you have all shared here, thank you all and especially Dave.

Some pages ago you all discussed about the possibility of submarines not having a sail, and that there were even some projects in this direction.

While the hydrodynamics would undoubtedly be increased, I think we should not forget that a sub (even a big one) has a low profile, and consequently it does not ride the waves very well. Therefore in my opinion it would be very hard to operate a sub on the surface in rough weather without a tower.

A modern sub theoretically does not need to sail on the surface, but this possibility cannot be completely ruled out, can it ?

Speaking of which, I wonder what subs did in ww2 in extremely rough weather. Of course, staying submerged saves a lot and avoids the complete mess of not being able to eat something without sticking the fork in your eyes, but they needed to recharge the batteries. How are the storms in the pacific compared to the ones in the Atlantic ?

Dave, could you tell us a little about the procedures aboard a diesel sub in stormy weather ? Do you adopt the maximum possible buoyancy ? Trimming the boat must be a hell of a task.

I can only imagine that in a serious storm you would be completely swept off the bridge (das boot comes to my mind, even though I cannot say how realistic that scene was created) and the boat would just either completely submerge in a big wave, or jump out of the water between the waves.

:88) did I say something dumb ?

[Subnuts]

Quite a few people have asked about late-war US submarine countermeasures, but not much information seems to be available out there. In Thunder Below Eugene Fluckey mentions using a large number of decoys while being hunted by a DD in shallow waters, but not much is actually said about them.

I recently bought a copy of Friedman's US Submarines Through 1945, which includes a few paragraphs on the subject, which I'll post here for anyone curious.

A submarine decoy program began in April 1943. Evolved from ASW training aids (echo repeaters) that the University of California Division of War Research (UCDWR) began to develop in 1942, decoys could be released from a submarine's 3-inch signal ejector tube and from her torpedo tubes. NAC was a barrage jammer with only limited output at any one frequency band. After tests on board an S-boat in February 1944, 450 NACs were ordered in June 1944; that increased to 5,450 in August. Another 5,000 NAC-1s were ordered in June 1945. A total of 4,308 were supplied to the submarine force during the war (contracts were cut back drastically at the end of the war). NAC proved only partially effective against experienced sonar operators. Its successor, NAH, used a high-velocity tape or disk recorder to pick up the sonar ping, then retransmitted it for 15 sec, beginning 0.10 sec after it arrived. It worked over the 10-30 kHz band. Development began in May 1945.

NAC did not move through the water like a real submarine. Work on a self-propelled NAD began in May 1943. The 3-inch NAD-3 simulated a submarine running at periscope depth at 120 turns. It could not accommodate a sonar repeater. A 6-in (diameter) decoy ejector was proposed; beginning in December 1943, an enlarged NAD-6 (6 in x 48 in) incorporating a repeater was designed to fit it. The new ejector was then canceled, and NAD would have to be fired from a torpedo tube. UCDWR enlarged NAD again (the 10-inch NAD-10 was made from an M30 mine body). The first NAD-6, carrying a sonar repeater, was completed in August 1944. BuShips demanded a simulator; a redesigned NAD-6 was tested in October 1944. Contracts for 500 NAD-6s and 500 NAD-10s were let late in 1944 and doubled in 1945; at the end of the war they were cut back to 500 each. These decoys held a straight course within two degrees so that the launching submarine where they were and evade away from them; gyro angle was preset to within plus or minus 90 degrees. NAD-3 ran at 5 kt at a depth of 50 ft and slowed to 3 ft to begin noisemaking at a preset distance. NAD-6 ran out of a torpedo tube at 4 kt; noisemaking began after 35 sec, and lasted 30-35 min. NAD-10 ran out at 7 kt, then slowed to 3.75 kit after 1 min; it lasted an hour. At lease some NADs were in fleet service in the summer of 1945.

David Taylor Model Basin began work in 1944 on NAE, a mechanical noisemaker derived from the towed FXR and effective above 6 kHz. Mk 1, a wideband masker, was field-tested in October 1944 and operational in the spring of 1945. Mk 2, introduced in the summer of 1945, differed from Mk 1 in that it could be launched down to 400 ft and its supporting balloon hovered below the surface of the water so that it was not visible from the air. Mks 3 and 4 were high-frequency maskers and jammers. NAE was considered effective at high sonic and supersonic frequencies and could even jam some sonars, but it was less effective at lower sonic frequencies. Postwar, it was developed mainly as a rocket-fired noisemaker (acoustic torpedo countermeasure) for use by surface ASW ships.

UCDWR and David Taylor conceived the NAG in 1943 as a lower-frequency companion to NAC to counter hydrophones in the 0.1-10 kHz range. A second sound head was later added, so that it could also operate at supersonic frequencies. NAG was under test at the end of the war. There were also false target shells (FTSs) and false target cans (FTCs). MIT designed pepper signals (Mk 14 and Mk 20) to mask submarine self-noise at sonic frequencies in shallow water. Reverberation would add its own masking; in deeper water, sonar operators could maintain contact between explosions.

A combined-use doctrine was quickly worked out. If the submarine was not sure that the enemy had contact, she launched an NAD or ejected FTSs and FTCs. If the enemy had contact, quantities of NACs and NAEs could jam receivers, confuse an attack, and break contact; then FTSs and FTCs would be ejected to add to the confusion. Once contact was clearly broken, an NAD emerging from the masked area would attract attention. The submarine had to choose her evasive course so that the NAD emerged before she did. Decoys always had to be ejected in rapid succession to avoid forming a trail that pointed to the submarine. These ideas and decoy categories (static noise beacon, mobile submarine simulator) have persisted ever since. Analogous radar beacons were developed to decoy radar-directed ASW aircraft. Hopes of an antisonar coating were not realized.

[TorpX]

I'm not sure what to make of all that. I'm guessing none of these complicated devices were modeled in SH4.

[DaveyJ576]

On the subject of the S-Boats, what is that funny little ball that's sticking up out of the deck near the bow?

As a few other readers have stated, that is the ball shaped receiver array for the S-boat's JK high frequency passive sonar. Frequently, mounted just below it was a bar shaped array for the SC low frequency sonar. The original shape for the JK was a flat plate. However, water turbulence prevented it from being used at speeds above 5 knots. The Naval Research Laboratory developed the spherical cover. It was so effective it effectively doubled the maximum sonar speed. It was 19" in diameter. The S-18 group had a rated top submerged speed of 9 knots and the S-42 group at 9.5 knots. So this simple spherical cover allowed the use of the sonar up to the maximum speed of the boat.

[DaveyJ576]

Anyway, about 2/3rds though the book, Beach makes a comment that the Negative Tank, unlike the other tanks is vented directly into the submarine. In the story he relates a circumstance where during an emergency dive, the negative tank was not blown when it should have been and when they blew it at a deeper depth it caused discomfort in the submarine.

Beach is pretty accurate in his books. But is this true?

Negative Tank vents only into the Submarine?

Why? is this to help conceal the submarine during the dive?

It is my understanding/(misunderstanding?) that during a normal dive, the negative tank is flooded, but when the submarine is on the way down, it is blown at a relatively shallow depth. The purpose of the negative tank is to give the submarine that extra kick to get under faster.

By venting the Negative tank into the submarine, there would not be a big sub fart of air telling the enemy where the sub is.

Is this correct or do I need to go back to lubbing land again?

Platapus:

You answered all of your own questions, and accurately I might add! When surfaced, the negative tank is kept full (or nearly so depending on the calculated state of the boat's buoyancy). You do this for the very reason you mentioned: it provides that extra amount of negative buoyancy needed to submerged the boat fast on a crash dive. Once under, the tank is blown to a pre-calculated "mark" that will restore (when combined with adjusting the amount of water ballast in the trim tanks) the desired neutral buoyancy. If circumstances prevented you from blowing the tank at periscope depth, you would obviously have to use increasing amounts of air pressure to empty the tank the deeper you were at the time. You eventually have to vent this air if you want to refill the tank and the air has to go somewhere. Venting it over the side would give off telltale bubbles so it is vented inboard. This would raise the internal air pressure and after a while this gets very uncomfortable for the crew.

BTW, Ned Beach wrote two sequels to "Run Silent, Run Deep", and are both excellent reads in their own right. "Dust on the Sea" picks up where the first book leaves off and completes the WWII portion of the trilogy. "Cold is the Sea" jumps to the Cold War era and follows Richardson after his promotion to a nuclear submarine squadron commander and deals with a Soviet submarine incursion to the Arctic.

Beach wrote the original RSRD in his off time while serving as a naval aide to President Eisenhower. It was a best seller and turned Beach into a semi-celebrity while still serving in the Navy. He also wrote several non-fiction books, one of his best being "The Wreck of the Memphis". This is the story of his father's command, the armored cruiser USS Memphis (ACR-10) and how it was wrecked by a freak tsunami while in harbor in the Dominican Republic. This was a gripping, thrilling tale and Beach did a masterful job of writing. I highly recommend any of this books.

[sharkbit]

Platapus:


BTW, Ned Beach wrote two sequels to "Run Silent, Run Deep", and are both excellent reads in their own right. "Dust on the Sea" picks up where the first book leaves off and completes the WWII portion of the trilogy. "Cold is the Sea" jumps to the Cold War era and follows Richardson after his promotion to a nuclear submarine squadron commander and deals with a Soviet submarine incursion to the Arctic.



Just curious-What do you think of Beach's accuracy?

I always felt they were extremely detailed and accurate, as well they should be considering his service. His narrative of approaches and attacks, especially in "Dust on the Sea", seem extremely detailed and very realistic. I've learned a ton just from those books as opposed to the 30 second approaches depicted in movies or the glossed over attacks in some books.

I'll definitely second your recommendation on the trilogy :yeah:. I've read all three countless times. In fact, I had to replace my copy of "Dust on the Sea" last year-it was falling apart. "Run Silent, Run Deep" isn't to far from falling apart as well.

:)

[DaveyJ576]

Speaking of which, I wonder what subs did in ww2 in extremely rough weather. Of course, staying submerged saves a lot and avoids the complete mess of not being able to eat something without sticking the fork in your eyes, but they needed to recharge the batteries. How are the storms in the pacific compared to the ones in the Atlantic ?

Dave, could you tell us a little about the procedures aboard a diesel sub in stormy weather ? Do you adopt the maximum possible buoyancy ? Trimming the boat must be a hell of a task.

I can only imagine that in a serious storm you would be completely swept off the bridge (das boot comes to my mind, even though I cannot say how realistic that scene was created) and the boat would just either completely submerge in a big wave, or jump out of the water between the waves.

A modern nuclear submarine can obviously go deep and ride under any storm, as long as the water is deep enough. When the boat is at deep submergence, there is very little sensation of movement. It feels very much the same as sitting alongside the pier.

How deep you would have to go to avoid a storm would obviously depend on how strong the storm is. I have been at 150 feet and could still feel the effects of the wave action, although it was greatly reduced.

Diesel boats are a whole other story. When submerged, diesel boats run on batteries, which will be depleted in fairly short order. A USN fleet boat could run for about 15-18 hours at three knots on the battery, assuming the battery was new and fully charged upon diving. This may actually sound like a long time, but remember that is at three knots, which is three nautical miles per hour, a distance of about 6000 yards in an hour. The average person can walk faster than that. If you go faster to cover a greater distance, the battery depletes it's charge faster. At a flank bell the battery will be completely drained in an hour, and you will still only have moved about 8-9 nautical miles.

What am I getting at? Well, the limited speed and endurance of your average diesel-electric submarine while submerged precludes diving to ride out the storm. Therefore your only option is to ride it out on the surface! This is not a pleasant experience. The low height, low freeboard, and the rounded hull shape all make for a very rough ride in heavy seas. Blowing or pumping out ballast to make the boat ride higher is actually counterproductive; it raises the center of buoyancy and results in the boat rolling even worse. It is not uncommon for a fleet boat to take "green water" over the bridge, that is for the boat to go completely submerged for short periods while it rides up and down on the waves. In these circumstances you would have to close the bridge hatch or the conning tower will flood. The lookouts and bridge watch would have to be lashed to their stations to prevent being washed over the side. In many cases the Officer of the Deck (OOD) would send the lookouts below for safety sake. Only the OOD and the Quartermaster would remain topside.

Inside the boat conditions get bad. Walking is very difficult and food and dishes go flying. Usually the cooks will secure the galley and provide only sandwiches for the crew. The best part of the boat to be in is right in the center in crew's mess. Due to it's location in the center it is moving the least. The worst areas are the forward and after torpedo rooms. Being at the very ends they are moving the most and riding out a storm in those compartments is like riding a roller coaster. It will make all but the most salty of sailors seasick. No one sleeps and trying to keep your balance and constantly holding on is actually quite exhausting and the crew gets tired quickly.

Another factor is the location of the main air induction valve for the diesel engines. On a fleet boat it is directly aft of the conning tower and just above the main deck. Low to the water, it will have a tendency to take in water during rough weather and the engine rooms bilges will fill up quick, requiring constant pumping with the drain pump. You also run the possibility of flooding the engines through the intake manifolds and if that happens you will have dead engines and the makings for a very bad day.

On December 3rd, 1943 the USS Sailfish (SS-192), under the command of LCDR R.E.M. (Bob) Ward surfaced into the teeth of a typhoon off the coast of Japan and commenced an attack on a Japanese task force. The seas were "mountainous" and the wind was estimated to exceed 50 knots. His approach was hazardous as any attempt at speed caused the bridge to take green water. The presence of escorts forced him to make several attacks, some submerged and some surfaced. Depth control at periscope depth was nearly impossible in the seas; he was alternately completely submerged with the scope under the water, or broached and on the surface. In desperation he submerged to 90 feet where depth control was a little easier and commenced a sonar approach. But the rough seas again botched his approach and the target passed astern. Angry in his belief that he had lost out on sinking a carrier, it wasn't until later that he and the crew learned that their earlier attacks had been successful. The carrier Chuyo had been mortally wounded and did indeed sink.

The Pacific can host some pretty awesome storms. In 1986 on a run from Japan to the Philippines, my old Darter ran through two separate typhoons. We lost one of our topside sonar domes and the aft marker buoy broke loose. One of the worst spots is the Bashii Straits north of Luzon. The bottom shallows compared to the surrounding seas and this magnifies the wave action. There were several times that we secured the bridge watch and brought everyone below. We raised the snorkel mast so that the main induction was above the waves and we ran along on the "surface", but in submerged mode. We did go deep every once in a while to give the crew a rest, but would eventually have to come back up to charge batteries.

I have spent my entire Navy career in either the Pacific, the Gulf of Mexico, or the Persian Gulf so I can't directly comment on the conditions in the Atlantic. But some of my shipmates have and their stories of the north Atlantic storms are the stuff of legends.

[DaveyJ576]

Just curious-What do you think of Beach's accuracy?

The accuracy of his novels is top notch. Beach is an incredible writer and his narrative brings everything to life without overwhelming you with technical minutiae.

Beach and most of the other good authors will sometimes downplay the technical side because of the necessity of writing for a wide audience, an audience that may not know the difference between a TDC and an SJ. Beach did a great job of balancing the somewhat conflicting desires of writing a technically and historically accurate novel while at the same time appealing to a wide and only partially informed audience.

The ultimate edition of RSRD is in the U.S. Naval Institute's Classics of Naval Literature series. It is a finely crafted hard bound edition and should last for decades. It comes with a ribbon page marker. "The Wreck of the Memphis" is also available in this series. I have both books and they are true treasures of my collection. See this link for more info:

http://www.usni.org/store/books/classics-naval-literature/run-silent-run-deep

[Platapus]

You answered all of your own questions, and accurately I might add!

Thank you for your kind words. I try to figure things out before posting here. I greatly appreciate your contributions to this thread. You give the straight poop and your are patient with lubbers like me.

This is one of my favourite threads on this site.

[Sgt Hotcliff]

Hey mates!

just want to say I just found this thread and will have trouble playing SH4 now, with all this info to read! :)

Also found an interesting Manual of Mk14 and 23 Torpedoes at
http://www.hnsa.org/doc/torpedo/index.htm

Thk's
Hotcliff

[sharkbit]

I don't know if this has been asked yet, but...
Were torpedoes able to be reloaded while on the surface or did they normally dive to reload?

I've never read anything definitive but I've gotten the impression that they could be in calmer seas.

I would think in seas that were even a little rough, it would be near impossible and extremely dangerous.

In game, I've always tried to limt my reloading to calmer seas(under 10 m/sec wind) and not while going balls to the walls around convoys and such. I try to wait until I'm submerged or I'm away from the action and I can slow down to do it.

Thanks.

:)

[Rip]

The accuracy of his novels is top notch. Beach is an incredible writer and his narrative brings everything to life without overwhelming you with technical minutiae.

Beach and most of the other good authors will sometimes downplay the technical side because of the necessity of writing for a wide audience, an audience that may not know the difference between a TDC and an SJ. Beach did a great job of balancing the somewhat conflicting desires of writing a technically and historically accurate novel while at the same time appealing to a wide and only partially informed audience.

The ultimate edition of RSRD is in the U.S. Naval Institute's Classics of Naval Literature series. It is a finely crafted hard bound edition and should last for decades. It comes with a ribbon page marker. "The Wreck of the Memphis" is also available in this series. I have both books and they are true treasures of my collection. See this link for more info:

http://www.usni.org/store/books/classics-naval-literature/run-silent-run-deep

That is the version I have, and I got it for a song on amazon. My first try to get it resulted in finding out the book store didn't actually have it anymore. But like Mush I was persistent and got the *%#*% thing eventually. To be passed on to my son when he is old enough. :up:

[TorpX]

I don't know if this has been asked yet, but...
Were torpedoes able to be reloaded while on the surface or did they normally dive to reload?

I've never read anything definitive but I've gotten the impression that they could be in calmer seas.

I would think in seas that were even a little rough, it would be near impossible and extremely dangerous.

In game, I've always tried to limt my reloading to calmer seas(under 10 m/sec wind) and not while going balls to the walls around convoys and such. I try to wait until I'm submerged or I'm away from the action and I can slow down to do it.

Thanks.

:)


I have had the same view of this as you.

However, I am reading Thunder Below!, and during their 10th war patrol, he comments on this issue. Fluckey planned out an attack on a well escorted convoy in very bad weather, 40 kt. winds. He said the plan was to reload on the surface, but the torpedo room crews would probably need some help. He was obviously concerned about it; the potential for injury, and told the crew to let him know if they were wallowing around too much.

[DaveyJ576]

When the USS Nautilus (SSN-571) first went to sea for exercises with the fleet in 1955-56 the incredible performance advantage she enjoyed over a conventional diesel-electric GUPPY boat shocked many naval strategists. The sudden realization that she nearly rendered all existing anti-submarine warfare (ASW) techniques obsolete hit the establishment like a ton of bricks. A conference was called together in the late summer of 1956 at Nobska, Massachusetts to study the problem. One of the main issues the attendees tackled was how to hunt and destroy a high speed, high endurance, deep diving nuclear submarine.

One of the solutions they came up with was (predictably for the 1950's) to nuke it. A developmental outgrowth of the Nobska study was the Mk 45 ASTOR (anti-submarine torpedo). With an 11 kiloton yield W34 fission warhead, the Mk 45 would overcome the limitations of the existing sonar and tracking systems and largely negate the speed and depth advantages of a nuclear submarine through good old fashioned brute force.

The Mk 45 was a 19 inch diameter swim out weapon that was 19 feet long and weighed in at a 2300 lbs. It was an electric torpedo of a relatively simple design. It had a range of approximately 7 nautical miles (14000 yards) and ran at a speed of 40 knots. It had no internal guidance or sonar systems other than a gyro. It was guided to the target via a control wire back to the firing sub. U.S. nuclear weapons doctrine of the day dictated that the weapon could not be allowed to auto-burst via it's own systems. It had to be detonated by the firing sub's crew at the appropriate moment (hence the control wire). The 11 kT warhead had a hard kill radius of 8000 yards. In other words, if your target was within that radius when the weapon detonated, it was dead, no joke. At 12000 yards the weapon could still be lethal, although the probability of a kill dropped quite a bit. At 16000 yards the target stood a reasonably good chance of surviving. It entered service in 1963 and was finally retired for good in the 1979 as the highly capable Mk 48 came on line.

There was a bit of gallows humor amongst the submarine crews that carried this weapon to sea. It was said you were assured of two kills anytime you used a Mk 45, your target and yourself. Remember that in the early 1960's the vast majority of the USN submarine force was still made up of diesel-electric GUPPIES and the new Tang, Darter, and Barbel class diesel "fast" attack boats. The maximum speed of these boats varied between 15 and 18 knots. At those speeds the battery would be completely dead in about a half hour. The concern was that if you fired a Mk 45 at an enemy it would be virtually a suicide shot. You wouldn't be able to get away from it fast enough to survive the detonation of your own weapon.

The hard kill radius of the weapon was 8000 yards, with a good probability of a kill out to 12000 yards. Let's assume best case scenario and say you obtain a firing solution on your target at 14000 yards. You fire your Mk 45 and she is running to your target at 40 knots. It will take about 10 1/2 minutes for the weapon to run that far. You can't maneuver and run away to increase the range. Remember the weapon has no internal sonars or guidance, you have to guide it to the target with your boat's own sonars, meaning you have to keep pointed at the target and stay slow and quiet. You send the command for the weapon to burst when it hits the calcuated range of 14000 yards and you wait for the shock wave to hit, fingers crossed.

Accurately tracking a submerged target at 14000 yards was problematic at best in those days. You wanted to rely on passive sonar so that you wouldn't give away your presence with active sonar pings. This made accurate ranging very difficult. Tracking ranges of 9 to 11000 yards were more realistic, and often it was less than that. This gave you precious little room for error when using this weapon. Later advances in sonar increased detection and tracking ranges and made the use of the Mk 45 a bit safer, but the submarine crews never really liked it and always viewed it with a great deal of justified trepidation. No one was sad to see it go when it was finally pulled from service.

If you want to see a Mk 45 torpedo, the USS Torsk (SS-423) museum has one on display on board the boat in Baltimore, Maryland, minus the warhead of course! The Torsk herself never carried the Mk 45 while in service as she did not have the proper sonars or fire control systems.

[DaveyJ576]

I don't know if this has been asked yet, but...
Were torpedoes able to be reloaded while on the surface or did they normally dive to reload?

It was done quite often on the surface, but as you surmised, the more the boat moved the harder it was to load the fish. A rope and pulley system was used to pull the weapon into the tube. It was 100% muscle powered and with a weapon that weighed in at 3000 lbs a lot of Armstrong Engineering (:D) was needed to wrestle the fish around. If the boat was submerged, the diving officer would quite often put an up or down angle on the boat to give the TM's a hand.

[Ducimus]

12 minute Declassified navy film about the MK 45 torpedo:
http://www.youtube.com/watch?v=WKOEaPHxY5k

:D

[DaveyJ576]

12 minute Declassified navy film about the MK 45 torpedo:
http://www.youtube.com/watch?v=WKOEaPHxY5k

:D

Great stuff Ducimus! Thanks! Notice how the vid said 12000 yards max range? That's even worse! Almost within the kill zone!

[TorpX]

Watched the film.........WOW :doh: I am reminded of Dr. Strangelove.


Two questions come to mind:

Wouldn't it make more sense as an air launched torpedo?
Why not use a fuel-oxygen powerplant for longer range?
Thank God no one ever used one.

[kraznyi_oktjabr]

Watched the film.........WOW :doh: I am reminded of Dr. Strangelove.


Two questions come to mind:

Wouldn't it make more sense as an air launched torpedo?
Why not use a fuel-oxygen powerplant for longer range?

Thank God no one ever used one.

1. There was nuclear tipped version of RUR-5 ASROC missile. If I remember corretly missile deployed nuclear depth charge.
2. Japanese used fuel-oxygen powered torpedo called Long Lance during World War II. Problem with torpedos using oxygen is their extreme flammability. If I remember correctly Japanese surface vessels sometimes disposed their torpedos when under air attack as single hit to torpedoes could cause them to explode and destroy or heavily damage the ship.

Imperial Japanese Navy tested fuel-oxygen torpedo in subs but they were not success, unfortunately I don't remember why. As speculation I would imagine that leaking "secondary air tank", which was code name for tank containing pure oxygen, could cause quite a hassle onboard submarine. When abnormally high level of oxygen is present many objects normally non-flammable can ignite spontaniously.

All this comes from memory so errors are likely. Please correct me as necessary.

[TorpX]

kraznyi,

My questions were, in a sense, rhetorical. What I was trying to say was that, a nuc torpedo with a danger radius that equalled it's range was a rather poor weapon, and that there were other tactical options that could have been explored.

[kraznyi_oktjabr]

kraznyi,

My questions were, in a sense, rhetorical. What I was trying to say was that, a nuc torpedo with a danger radius that equalled it's range was a rather poor weapon, and that there were other tactical options that could have been explored.

Ah, okay. :)

[Nuc]

kraznyi,

..... and that there were other tactical options that could have been explored.


There were more options as development proceeded. Sub museum in Groton has a great display on Cold War weapons systems inclluding SUBROC and others
http://www.designation-systems.net/dusrm/m-44.html

[TorpX]

@Nuc

Good material there. Heard of the Subroc, but didn't know the details. Certainly a much better weapon than the Mk 45. Odd that it was taken out of service without any replacement, though.

[Nuc]

@Nuc

Good material there. Heard of the Subroc, but didn't know the details. Certainly a much better weapon than the Mk 45. Odd that it was taken out of service without any replacement, though.


Budget cuts and end of the Cold War:

http://www.designation-systems.net/dusrm/m-125.html

[Elektroniikka-Asentaja]

Ahoy! This may have been asked already but as I'm lazy I didn't even try to wikipedia (yea it's a verb xD) this out..

As the ships sink only because of flooding (makes sense), how did (sub)captains measure destroyed if the ship was just burning furiously, for example after deck gun attack, but not sinking?

[Platapus]

I am re-re-re........re reading Ed Beaches "Run Silent Run Deep" for the millionth time. What a great book!

The book opens up with Bledsoe being examined for command of the S-16. Beach describes Bledsoe as an NROTC Lieutenant. The action takes place in December 1941.

Was it common for a non-Academy officer to have a command of a submarine that early? I know that later in the war, this happened.

Was it common for NROTC grads to have command of a submarine at the start of WWII?

I can't go back to lubbing my land until I know.

[stephenf555]

Hi folks,
Reading an encyclopedic book on the uboots at the moment. I was reading about the Type XXI, which seems like the first sub to be designed similarly to today's modern subs.

It struck me that it was kind of weird that it took until this point (1943?) to design a sub with a hydrodynamically efficient exterior. I would assume that any naval engineer worth his spanner would know that all the protrusions and flooding outer hull would greatly affect underwater speed. I know that the earlier subs were designed to spend most of their time on the surface and to be able to submerge for attack etc, but it still amazes me that they were covered in so much equipment.

So, I guess I'm wondering is why it took so long for them to design a hydrodynamic sub? Was it an engine issue...that only then did they get appropriate electric motors and batteries capable of spending longer times under water? Or was it that the deck guns etc were becoming redundant later on in the war? Or was it simply that one day they noticed that is they got rid of all the extraneous stuff the boat would be much more efficient underwater...though as I said, I assume they knew this long before?

[Platapus]

As I am sure Steve will chime in, the S-boats designed in the 1920's were designed for high submerged speeds. While the S-Boat could not travel faster underwater than it could on the surface, it came close 15 knots surfaced 11 Knots submerged.

[stephenf555]

Interesting.
So why then the return, or continuation at least, of designing boats that were much slower submerged, with deck guns and AA and all that? Did the fast running submerged boats not work strategically for some reason?

I suppose that it may have just been down to battery characteristics...if you can only stay running submerged for a few hours and it takes a few hours to recharge on the surface, then you're going to have to spend a lot of time surfaced, and therefore you require AA and deck guns, and hence you go slower when submerged.

[Platapus]

Interesting.
So why then the return, or continuation at least, of designing boats that were much slower submerged, with deck guns and AA and all that? Did the fast running submerged boats not work strategically for some reason?

I suppose that it may have just been down to battery characteristics...if you can only stay running submerged for a few hours and it takes a few hours to recharge on the surface, then you're going to have to spend a lot of time surfaced, and therefore you require AA and deck guns, and hence you go slower when submerged.

I would like to recommend you read "Ship Killers"

http://www.subsim.com/radioroom/showthread.php?t=178746

This book is one of the few that goes into the strategic intent of torpedoes (and submarines). It explains how the Navy, in the 1920's-1930's) intended to use submarines.

That may help you understand why the design of submarines changed from a more hydrodynamic design to one that is more suitable for surface use.

As it turned out the 20-30' Navy's plan did not occur and submarines were used in a more individual tactical manner.

Anyway, I can highly recommend this book.

Good luck

[Nuc]

I would like to recommend you read "Ship Killers"

http://www.subsim.com/radioroom/showthread.php?t=178746

This book is one of the few that goes into the strategic intent of torpedoes (and submarines). It explains how the Navy, in the 1920's-1930's) intended to use submarines.

That may help you understand why the design of submarines changed from a more hydrodynamic design to one that is more suitable for surface use.

As it turned out the 20-30' Navy's plan did not occur and submarines were used in a more individual tactical manner.

Anyway, I can highly recommend this book.

Good luck

Another good reference on the evolution of the design is:
http://www.amazon.com/U-S-Submarines-Through-1945-Illustrated/dp/1557502633/ref=sr_1_1?ie=UTF8&s=books&qid=1300182971&sr=8-1

[Platapus]

Did the US Navy ever build SKINC?

I know that there were some tests of the technology, but I have not been able to find out if either a prototype or an actual production version was ever made.

The Internets Tubes are lacking in detail on this.

[Oleif]

Hello all. I was wondering if I understand this correctly. German Uboats' diesels were directly coupled to the driveshaft during surface running, when underwater the driveshafts were connected to the electric motors and the diesels disengaged. American fleet boats however, the diesels were used exclusively as generators and when surface running the dieseles powered the electric motors directly without battery use. So in effect the diesels were never directly coupled to the driveshaft. Is this correct?

[Sailor Steve]

That is correct:
German: http://www.uboatarchive.net/U-570ONIReport.htm Section II-C-1

American: http://www.maritime.org/fleetsub/diesel/chap1.htm#1D

[Oleif]

Thanks Steve, untill I road trip to Manitowoc this summer does anyone have a good photo collection of life inside a gato or any other fleet boat??

PS. During a deep dive and or a depth charging, would any crew remain in the conning tower or is that part of the boat sealed off? It seems a bit vulnerable.

[Platapus]

I am re-re-re...-reading O'Kane's Clear the Bridge.

I have a question about what he wrote at the start of Chap 2

All hands execpt the executive officer, his assistant navigator - a chief petty officer (CPO) - and me [O'Kane] would stand watches either in their specialties, or manning the radar, as ....

The Captain and Exec don't stand watches, that's understandable. Why wouldn't the Assistant Navigator not stand a watch when presumably the Navigation Officer would?

Also, I would have assumed that the Chief of the Boat would also not stand a regular watch as he would have to be everywhere/anywhere in the sub.

Can someone learn this lubber o' land sumpten about watch standing? :88)

[Stealhead]

He is meaning I think that the XOs assistant is a Senior NCO so he could be any E-7,E-8,or E-9 not the Chief of the Boat they are not one and the same person.

But it is confusing based just on the context of that sentence. I am not sure why it says assistant navigator in reference to a CPO that does not make sense seeing as any navigator would be a commissioned officer not an SNCO or this is a Navy term I don't know.

The CPO he is talking about does not appear to be the COTB though just an SNCO which you are going have more than one of even on a sub one of them being the COTB.You are correct the Chief of the Boat would be going around the boat maintain discipline by being stern or praising depending on what he saw and I dont see why that would be different in the Tangs case.

The Chief of the Boat is one of the all hands he refers to.Though different sub commanders did have different systems for parts of watch I dont think any of them would take the Chief of the Boat away from his primary duty of maintaining discipline of the enlisted men he cant do that standing next to the XO all day.

[TorpX]

I am re-re-re...-reading O'Kane's Clear the Bridge.

I have a question about what he wrote at the start of Chap 2



The Captain and Exec don't stand watches, that's understandable. Why wouldn't the Assistant Navigator not stand a watch when presumably the Navigation Officer would?


Have not read it recently, but I think the navigator was the XO.

[Oleif]

How was information loaded into the tube before firing? I assume there was a connection to the torpedo while the torpedo was in the tube to allow instant updates from the TDC and split second firing. Was there a wire leading to the motor? would a crewmember have to turn a knob or something then quick shut the door?

[sharkbit]

I believe rods went into the tube and into the torpedo that rotated to set the information into the torpedoes. They were automatically rotated based on info from the TDC or they could be manually set. They were withdrawn prior to firing.

In pictures of torpedoes I've seen, you can see the holes where the rods go into the torpedo.

:)

[Ducimus]

Thanks Steve, untill I road trip to Manitowoc this summer does anyone have a good photo collection of life inside a gato or any other fleet boat??


How about a virtual tour?
http://www.maritime.org/tour/index.php

[FADM Gryphon]

Probably not a new link but just incase. I was viewing the SS-383 USS Pampanito web site and came across the Fleet Type Submarine Manual Online. Here is the link to the online manual.

http://www.maritime.org/fleetsub/index.htm

[Daniel Prates]

The last two posts are just AWESOME!

[Sailor Steve]

Thanks for reviving the thread, FADM Gryphon. I somehow missed the following at the time, but I do have the answer.

How was information loaded into the tube before firing? I assume there was a connection to the torpedo while the torpedo was in the tube to allow instant updates from the TDC and split second firing. Was there a wire leading to the motor? would a crewmember have to turn a knob or something then quick shut the door?
There was a connection that ran through the tube wall to controls on the torpedo itself.
http://www.maritime.org/fleetsub/tubes/chap7.htm

[FADM Gryphon]

Thanks for reviving the thread, FADM Gryphon. I somehow missed the following at the time, but I do have the answer.

No problem. It is great to be part of a thriving community.

[White Owl]

How was information loaded into the tube before firing? I assume there was a connection to the torpedo while the torpedo was in the tube to allow instant updates from the TDC and split second firing. Was there a wire leading to the motor? would a crewmember have to turn a knob or something then quick shut the door?

Thanks for reviving the thread, FADM Gryphon. I somehow missed the following at the time, but I do have the answer.


There was a connection that ran through the tube wall to controls on the torpedo itself.
http://www.maritime.org/fleetsub/tubes/chap7.htm


I'm in the process of reading through the USS Pickerel's (SS-177) patrol logs, and thought of your question when I got to this part, excerpted from the 4th patrol log on June 9th, 1942: Not a specific casualty but considered worthy of mention is the fact that power setting of gyro angles on torpedoes has been impossible on this vessel since more than three months before war was declared. Attempts to remedy this condition had been continuous during that time with tender experts and the Arma Co. representative called in for advice. The friction and drag of the setting gear on the tubes is excessive and stalls the motor in the gyro angle setter, the latter operating perfectly when individual clutches on the tubes are disengaged. Hand operation has been used sucessfully throughout the war and is adequate under normal attack conditions. However, due to very low gear ratio, hand setting is slow and, for a quick change of targets, might cause some delay. Hand operation is definitely much more quiet than power and is equally as accurate as power operation since these gyro angle setters are power-operated hand-controlled in contrast to the fully automatic type installed in later submarines. In view of the forgoing, it is recommended that, if a Navy Yard cannot make power setting of a full tube nest certain and dependable, the power setting system be removed and the hand setting gear ratio be increased. This alteration could provide the reliability required of this instrument under war conditions.

[Sailor Steve]

Good find. Reports like that are always fun.

[carboneum]

Probably not a new link but just incase. I was viewing the SS-383 USS Pampanito web site and came across the Fleet Type Submarine Manual Online. Here is the link to the online manual.

http://www.maritime.org/fleetsub/index.htm



Awesome pages. Thanks a lot!

[Sailor Steve]

Awesome pages. Thanks a lot!
WELCOME ABOARD! :sunny:

Yeah, the fleet boat manual is old news for a lot of us, so much so we forget that a lot of folks haven't heard of it, let alone read it. Have fun. :rock:

[soopaman2]

I always wondered some things, and once again draw upon the collective knowledge here.

How did they get torpedoes from external storage and into the ship. Is there some kind of winch they had to help, or brute manpower. Torps had to be close to 400-500 pounds, no? Bruteing them in rough, or even slightly pitching seas had to be tough.

Did it have to come in through the conning tower hatch? Was that the only hatch?

Are external storage systems still in use today?

Sorry to bombard you with questions, just curious is all.:salute:

[Dread Knot]

US subs didn't use externally stored torpedoes, but U-Boats did.

First the boat had to find flat seas in an area where it was safe to be on the surface for that long. Just finding calm enough water in the North Atlantic could be quite difficult and as the war progressed finding someplace safe from detection for long enough to do it also became difficult. Once the torpedo was positioned in the open torpedo loading hatch the boat couldn't dive and that left it extremely vulnerable to attack, especially from the air.

Step one was to rotate the canister to the proper angle and open it. Then the portable winch had to be attached and the cables for the pulley system secured. Next, the torpedo had to be winched out of its container and onto a cradle that could then be positioned in front of the torpedo loading hatch. Lastly the torpedo had to be lowered into the boat through a forward hatch in the hull and stowed away just as they were when they were loaded directly into the boat back at base. U-boats generally dived in order to reload the torpedo tubes as the motion of the boat on the surface at sea made it too dangerous to try to do it there, especially after the detonator had been installed.

http://adjunct.diodon349.com/Uboats/Uboat_jpgs/u-boat-torpload.JPG

[Dread Knot]

Are external storage systems still in use today?
.:salute:

I'm not sure, but I doubt it given the hull shape of submarines today. It'd be almost impossible to stand on the those cyclindrical hulls while underway.

[Sailor Steve]

@ Dread Knot: Thanks for that picture! It's one I didn't have in my collection.

@ soopaman2: Here is a diagram of the process. Unfortunately it's not in English, but I think it gets the idea across.

http://i14.photobucket.com/albums/a325/SailorSteve/esquemacarga.jpg

And if you think that was bad, here's a series showing what it took to transfer each torpedo from a milch kuh.

http://i14.photobucket.com/albums/a325/SailorSteve/img02iq.jpg

http://i14.photobucket.com/albums/a325/SailorSteve/img003z.jpg

http://i14.photobucket.com/albums/a325/SailorSteve/img004kt.jpg

http://i14.photobucket.com/albums/a325/SailorSteve/img005tc.jpg

http://i14.photobucket.com/albums/a325/SailorSteve/Resupply.jpg

[soopaman2]

:O:Thanks you 2 (Dread Knot and Sailor Steve.):)

I was looking at the pictures with the milk cow tranfers, and just pictured the sheer loss from a lucky allied airplane.

They almost remind me of the old pictures from the Pacific Northwest loggers walking on a river of floating logs and prodding them downstream.

Some of us can never truly understand the constant fear, that these men laughed about.

[Arlo]

Anybody here participate in WWII submarine living history (reenactment)?

http://www.ss310.com/index.html

[Captain J. Borne]

The stories are many times more precious. But they are dying daily. I have spent dozens of hours on the "Through the Looking Glass" site. I've seen half of it. If these subvets don't look and trust some people outside their own rapidly dwindling number, all these stories will die with them. With the stories will go the truth about how they fought on both sides of the war.

Like any other real captain, it will go down with the ship!

[Grooveclubhouse]

Just wanted to say that I have read this thread from begining to end and have been absolutely facinated by it. The shear wealth of personal knowledge here and its accompanying links have taught me more than I ever thought possible and has been more interesting than playing the acutal game! :yeah:
Being new to this forum I thought I'd say Thank you to everyone who made this a great thread.

[TorpX]

I found a interesting link on the Matrix forum. It isn't submarine related, strictly speaking, but I thought this would be a good place to post it. It's a 1945 training film about the Mk 13 ariel torpedo, which goes into considerable detail about the late war developments in the Mk 13.


http://www.youtube.com/watch?v=WyU8tdpfIis&feature=youtu.be

[DaveyJ576]

Hey there! I have been away for a while, the Navy has kept me quite busy. I will be in and out for the next several months so I will try to participate the best I can.

However, I have been able to complete a few projects. One of them is Part Three of A Visual Guide to the U.S. Fleet Submarines series. Here is the link: http://www.navsource.org/archives/08/10idx.htm

This part covers the Balao and Tench class boats. If it seems that I am jumping around a little, you are right! I wrote the articles out of sequential order because I wanted to cover the boats that were the most frequently mis-identified first. I have started Part Four, which will cover the Porpoise/Perch class but it will be several months before that one hits the streets.

Comments and suggestions are greatly appreciated! Enjoy!

Dave

[magic452]

Welcome back Davey, :yeah: was wondering where you got off to.
Very nice work there. :salute:

Magic

[soopaman2]

Seemed the most appropriate place to ask. As the question I ask somewhat relates to Pacific sub Ops.

In the movie Run Silent Run Deep what is the sub type used.

I don't recall it mentioned but it appears to be a Baloa perhaps? I am unsure.

They all look like type VII's to me!:D

Yeah I do ask dumb questions sometimes.

Also I must say...Wow what a great film! I was born too late, and missed out on alot of cinematic genius. Driven by pure acting.

I am stuck with Micheal Bay/George Lucas/Steven Spielberg types who spend more on the CGI, than the acting or script.

[Hinrich Schwab]

Seemed the most appropriate place to ask. As the question I ask somewhat relates to Pacific sub Ops.

In the movie Run Silent Run Deep what is the sub type used.

I don't recall it mentioned but it appears to be a Baloa perhaps? I am unsure.

They all look like type VII's to me!:D

Yeah I do ask dumb questions sometimes.

Also I must say...Wow what a great film! I was born too late, and missed out on alot of cinematic genius. Driven by pure acting.

I am stuck with Micheal Bay/George Lucas/Steven Spielberg types who spend more on the CGI, than the acting or script.

You are correct that it is Balao Class. The USS Nerka was a cancelled Balao Classe boat project in real life. In the movie, the USS Redfish played the Nerka.

[Mister_Spok]

Mornin' sailors!

I have a question regarding real life use of S-boats. I had a hard time searching any useful info on Sugar boats, so my last try is to ask here.

Due to pre-war doctrine, skippers, if operated in 500nm radius of enemy air bases, stayed underwater for daytime. So, did S-boats have that much renewable oxygen supply do remain submerged for 8-12 hours? I mean - RENEWABLE supply.

P.S. I'm already here, so I couldn't not ask - how long S-boats could stay on patrol, until their food and fresh water supply depledes?

[Platapus]

I can only cite one data point.

On 1 Sep 20 the SS-110 (USS S-5) sank during a dive. The crew was able to blow the stern out of the water, but the crew had to cut a hole in though the skin to get air inside. It took them 36 hours to cut a 3" hole through the hull to get air inside.

So for that one data point, the crew could survive at least 36 hours in an S-boat.

http://www.hampton.lib.nh.us/hampton/history/ships/usssqualus/lossofsqualus.htm

http://en.wikipedia.org/wiki/USS_S-5_%28SS-110%29

[Rockin Robbins]

Comments and suggestions are greatly appreciated! Enjoy!

Dave

Ahoy Dave! I'm sounding the alert here! over in a neighboring thread we have a couple of submariners discussing passive TMA. Look at the middle and toward the end of http://www.subsim.com/radioroom/showthread.php?t=191882. One of them claims that WWII subs did that.

Can you come up with any target tracked during the war by any sub using passive TMA techniques? I'm not talking about laying down a track by visual, active sonar or radar observations and just using the sonar bearing to fix the target's position along the track, I assume that was done quite often. I mean total TMA derived target course and speed accurate enough to shoot by.

We'd appreciate any info.:salute:

[Carthaginian]

If any of you gentlemen were to purchase the following books, which of them (besides all of them) would you recommend getting. At 17, I was one signature away from getting into the Silent Service (Dad wanted me to go to college, which only lead to me being a ground-pounder when the shooting started) and though it didn't happen, I've always been fascinated by submarines... hence my being here.

So... I am planning on buying the most informative version of this book, and there are three: Fleet Boat, GUPPY and 1963 (some nuke stuff). Which would you go for- and why?

The Fleet Submarine (http://www.periscopefilm.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=57&category_id=31&option=com_virtuemart&Itemid=1)

GUPPY (http://www.periscopefilm.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=129&category_id=31&option=com_virtuemart&Itemid=1)

1963 (http://www.periscopefilm.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=128&category_id=31&option=com_virtuemart&Itemid=1)

[Hylander_1314]

Go with the Fleetsub book.

[Carthaginian]

Hylander,

I'm interested in knowing, mostly, if anyone here who has been through BESS can tell me more of what is in each version of the book, and which book would be the most insightful. I will- regardless- purchase both the Fleet Boat book AND the color plate book later on... but for the first purchase, I want the one that can teach me the most.

[RDNK_PRD]

"The Department of the Navy consists of two major components: the United States Navy and the United States Marine Corps. Yes, to their everlasting chagrin, the mighty Marines are actually a part of the DON."

Ah you had to go and say it didn't you, one of the worst kept secrets of the USMC. LOL

Remember as Marines we hit the beach running but we had to float to get there.

[Gino]

Hylander,

I'm interested in knowing, mostly, if anyone here who has been through BESS can tell me more of what is in each version of the book, and which book would be the most insightful. I will- regardless- purchase both the Fleet Boat book AND the color plate book later on... but for the first purchase, I want the one that can teach me the most.

Check the HNSA website. There you can find the Fleetsub manual:
http://www.hnsa.org/doc/fleetsub/index.htm
I would not buy the color plate book. It's waaaayyy to small, and you can download those plates from the website. Print them on a 11x17 or A3 format and they look decent.

Groetjes,

[stanger]

I have a question (or two) about antennas: 1st: how it should be called? On one of the plans (Sargo or Pampanito) I saw its called "wing antenna", on others - its just antenna. Or it doesnt matter much?
2nd:
https://vfybla.blu.livefilestore.com/y1pu_RYxTXnt-DUQ81A6384F4Lq4fytUiBXnX9wwpyJnsPfWnNF-wz9gSUUUpyV1KEXEDmgoASDXY-TQpW5q1i11pzsGXShsOSh/wing%20antenna.jpg?psid=1
One of the antennas is raised; and attached to - if I can see right - to air search radar antenna, but at the same time, I didnt see it like that on ww2 photos. Was it some peace time thing, or the crew could take that cable, attach it when needed only? And if it was attached to SD antenna, was it moving with it?:)

[Hylander_1314]

Wing antenna, antenna, it doesn't really matter, unless you wish to speak of a certain one on the boat. And depending on what part of the country a guy came, it could be called an aerial too. Just depends on what they called it where he came from.

For the second question, do you have a pic, or link to one, it might help.

Sometimes enterprizing sailors would rig up things that only that particular boat had. Just depended on their skills and abilities to make things.

[stanger]

Thanks for the answer.
No, I dont have a pic, I was doing a little study of fleet boats plans found here (http://www.hnsa.org/doc/plans/index.htm), and noticed this little detail. I did look at photos I have on my HDD (over 200 of them :D), and didnt find anything, I will scan through some web sites, maybe will find something.

Maybe this one?
http://www.navsource.org/archives/08/0817212.jpg

Heres too:
http://navsource.org/archives/08/233/0823317.jpg

[Subnuts]

I was checking the San Francisco Maritime Museum's website today to see if they had any new material, and I stumbled across a bit of a goldmine in the process.

http://www.maritime.org/tech/drawings/index.htm

This site has dozens of original Bureau of Ships construction drawings for various Balao-class boats. The quality of scans varies from excellent to unreadable, but I can see spending hours studying these blueprints.

[Iron Budokan]

This is a wonderful and very informative thread. I have recently gotten back into SHIV and am having a lot of fun with the modded game. This thread with all its historical information and technical detail is a direct complement to that experience.

Thanks, guys! :)

[Dice Holder]

im looking for blueprints of subs the only problem is i need detailed blueprints

[Gino]

im looking for blueprints of subs the only problem is i need detailed blueprints

Have you tried: http://www.hnsa.org/doc/index.htm ?

I don't know how much detail you're looking for, but a trip to the National Archives could help...

[Bathrone]

This is a great thread and sincere thanks for everyone who contributed to the information. I read it all in one hit, fascinating

The thing that has crossed my mind more than once is what the submariners were expected to do with their adult urges? 80 days with no women! :D I guess atleast in port it would help the lesser desirable women to pickup a hot sailor date as I cant say I'd have any sort of standards left from 80 days without :arrgh!: Does she have a heartbeat? CHECK! Prepare to dive!

I wonder if it would be possible for people who've been on subs in a navy to talk about these issues in a way that doesnt attract the moderators wrath? From a tactical sense I seriously submit that the lack of sex in young males could have tactical drawbacks to their performance in operations.

The other issue I could see coming out of all this, is say young sailor has his liberty and runs a mock in the pubs, is too drunk to hookup a local woman, gets coerced by a local prostitute and he goes with that, when he manages to stumble his way back to the boat he's now got a sexually transmitted disease that will effect his performance on operations

For some reason it seems never to get discussed in submarine books that I've seen

[Lokisaga]

Hi all,
I'm wondering if someone can tell me a little bit about the warheads used in German and American torpedoes during WWII. Specifically, I'm wondering what the explosive power of Hexanite (the Kriegsmarine explosive of choice) and Torpex (USN) is in joules per kilogram. I'm trying to determine a standard frame of reference for comparing USN and Kreigsmarine torpedoes from this era.

Thanks

[TorpX]

I can't tell you as much as I would like, but I can give you a few hints.

First off, references give the warhead weight, but rarely say anything about the actual charge. I suspect the warhead wt. includes the casing, and perhaps the exploder as well.

As far as the explosives is concerned, I know the US used TNT at first, then adopted Torpex. I believe the IJN used picric acid or something based on it. I don't know much about Hexonite. I wouldn't give too much weight to explosive energy per kilogram. I don't think this correlates well with "effectiveness". Explosives were tested in various ways, and their suitability for a purpose was likely to be decided by a combination of factors. For instance, the detonation velocity, correlates well with the "shattering effect", where hull plates (or whatever) would be broken apart.

I found this list of some explosives on Wiki:
http://en.wikipedia.org/wiki/Relative_effectiveness_factor

Torpex wasn't on the list, but I've read that it was considered about 50% more effective than TNT.

By the way, I should note, some gamers use damage models, where a 100x charge is only does 10x more damage. (I consider this dubious when talking about ship hulls.) The overall model is obviously very important here.

[DieReeperbahn]

I have a question about what the crew could and could not do during their off duty time. Did they have the run of the boat, on deck, talk to their buddies, etc or were they restricted to the crew areas?

[TorpX]

The number of men on deck was always restricted. Otherwise, it would be too difficult to make an emergency dive, and the whole boat put in jeopardy. Beyond that, I don't know. Some of the crew, would not see the sun for the whole patrol.

[Redmane]

I can't recall where it came from or where it might be here (search?), but I read somewhere recollections from crew about how things were when in a patrol area. They would run submerged all day, surfacing after sundown, diving just before dawn. The air in the boat would get very foul, it was always very hot and uncomfortable as the "air conditioning" really helped only to keep the humidity down so conditions weren't so hard on the equipment in the boat. Because of this, most of their off-hours while submerged were spent sleeping to help conserve oxygen. Also, being ex-Navy (never was a submariner though) I can tell you that between normal working hours and a rotating watch schedule, 4 hours on, eight hours off is how it works, and then there are the dog-watches, 2 hours for those, there were alot of times when my sleep schedule was so messed up it was difficult to stay awake during normal working hours. So far as the ship I was on, we could go more or less anyplace on board, though hanging out on the bridge was not really an option, but I would often take a walking tour about the ship, even passing through the engineering spaces, though staying out of the way of course. There were cat-walks running through the area with a ladder access leading up into the stack, and I would climb up there and exit via the access hatch onto the upper deck, as there was almost always a nice view to be had there, and the breeze would be cool after feeling the heat in the boiler room.

[DieReeperbahn]

I suppose when the alarm sounded or battlestations, everyone would be back on duty?

[Redmane]

Yes, the actual term is "General Quarters" and every member of the crew had an assigned station, depending on rate and rating. Rating refers to your specialty, rate is rank, with respect to enlisted personnel. I was a Gunner's Mate, and since I was on a supply ship from which the AA gun mounts had been removed I was assigned to one of the damage control parties, which were stationed at various places throughout the ship. But yes, during General Quarters, everyone is expected to be on station and ready for action.

[Sailor Steve]

The thing that has crossed my mind more than once is what the submariners were expected to do with their adult urges? 80 days with no women! :D I guess atleast in port it would help the lesser desirable women to pickup a hot sailor date as I cant say I'd have any sort of standards left from 80 days without :arrgh!: Does she have a heartbeat? CHECK! Prepare to dive!
I was a surface sailor, but the logic, or lack thereof, is the same. You try not to think about it. You do other things. You take care of yourself, just like every young man does. I was overseas for several months, and never once strayed from my girlfriend back home. It was no more a problem than being a teenager and not having had that experience yet. You live with it.

From a tactical sense I seriously submit that the lack of sex in young males could have tactical drawbacks to their performance in operations.
Then you know little of human performance where sexuality is concerned. When you're on duty you think about the job. If you don't think about the job, and you make mistakes, you get in trouble. Mostly you do your job and don't worry about it.

The other issue I could see coming out of all this, is say young sailor has his liberty and runs a mock in the pubs, is too drunk to hookup a local woman, gets coerced by a local prostitute and he goes with that, when he manages to stumble his way back to the boat he's now got a sexually transmitted disease that will effect his performance on operations
This is why they have regular 'short-arm' inspections. Remember the scene in Das Boot where the sailors are all lined up in front of the Sani (Corpsman/Medic), getting checked? That's what they do, and that's how they do it. The biggest danger is that your crewmates will find out and give you grief for being unfaithful to your wife/girlfriend. Overall crew performance is unaffected.

There. Now it's been discussed. By a moderator. :sunny:

[fireftr18]

Yes, the actual term is "General Quarters" and every member of the crew had an assigned station, depending on rate and rating. Rate refers to your specialty, rating is rank, with respect to enlisted personnel. I was a Gunner's Mate, and since I was on a supply ship from which the AA gun mounts had been removed I was assigned to one of the damage control parties, which were stationed at various places throughout the ship. But yes, during General Quarters, everyone is expected to be on station and ready for action.

My understanding, on subs, most of the crew members had two jobs. One was a day to day job that's covered by regular duty shifts. Then, for lack of better term, a "general quarters" job. Which was covered by the members while "off duty." Is that accurate? Is it the same on a surface ship?

[Redmane]

My understanding, on subs, most of the crew members had two jobs. One was a day to day job that's covered by regular duty shifts. Then, for lack of better term, a "general quarters" job. Which was covered by the members while "off duty." Is that accurate? Is it the same on a surface ship?

Yes, I think this is fairly accurate. I'm not so sure about subs, since I was never on one, but I don't see why it would be much different. The crew is divided up into divisons, which relate to specialties. You have a normal work routine, which for the most part involves maintanence. For watches, your particular division, depending on what its specialty is, would be assigned a specific duty, for instance, deck division would handle all the lookout posts. As a gunner's mate my division was assigned to maintain the radar contact status board on the bridge. For General Quarters, once again the assignments are made, though this is based on the performance of the crew at their different jobs, that is, how efficient are they at doing "X?" Then there were some different aspects to the whole workings because being on a supply ship we also did underway replenishment. Transfer of supplies to other task force units while moving at sea. Once again, deck division would handle rigging and operating the tranfer equipment. I as a gunner's mate had the fun task of using a line throwing gun to send a starter line to the ship along side which would eventually be used to get the span-wire for a fuel hose or a high-line across and secured on the other side. So given the general purpose of the ship in question, some of these things would vary of course, but that's pretty much how it went in my experience.

[Nuc]

This is an interesting post war (1949) training film featuring footage of Tench, Balao and Guppy boats. It does describe wartime organization and support.

http://www.youtube.com/watch?v=367qVO9cQiU&list=PLuPhczO_xSu_dwXXMoD3g6YkBKodYfId4&index=6

[harishrajan96]

Did sub commanders during the war prefer attacking a convoy or blasting a lone merchant out of the water ??

[fireftr18]

I haven't read any of the books, only seen some of the movies. One thing I'm sure of is that an entanglement with a destroyer, especially a group of destroyers is a losing proposition for the sub. I think in real life any good sub skipper would much rather attack a lone merchant than a convoy using multiple escorts. You have to remember, their crew members were real person's so they're going to be cautious during attacks.
In the game, we know we're actually safe no matter what happens and the crew members are really only code in a computer program. If we get "killed," it's literally nothing more than a message on a computer screen. Knowing that, we will intentionally get much more risky than in real life.

[California-781]

I just want to know what is it like serving on a submarine, especially today?

[Aramike]

Did sub commanders during the war prefer attacking a convoy or blasting a lone merchant out of the water ??From everything I've read, skippers seemed to prefer finding whatever targets they could get. As such, they'd typical stalk out known sea lanes, and were just happy to find anything to shoot at. In the early war, skippers were somewhat risk-adverse, and were replaced by the more daring types such as Morton and O'Kane.

And those types of captains had absolutely no issue attacking a convoy.

[fireftr18]

Were they more daring? Or with knowledge gained had techniques developed that minimized risk? :06:

[Aramike]

Were they more daring? Or with knowledge gained had techniques developed that minimized risk? :06:There was certainly more knowledge and refined techniques, but engagements only got riskier. Skippers would do anything to avoid detection during an approach, and they seemed to relish the 1k-1.5k yards shot. From that distance, there's practically no way that escorting destroyers wouldn't get a decent bead on them after torpedo impact.

Bear in mind that the Mk 14 had a much, much greater range.

[Bubblehead1980]

Some were aggressive and risk takers, such as CO of USS Harder who liked to fight it out with Destroyers, with much success.Others were far too cautious and fearful. Some of the uber aggressive one's lived, some did not.Some of the cautious one's managed to sink a few(blind squirrel finds a nut once in a while) some did not and were relieved.The most successful skippers seemed to be those who had the proper balance.Slade Cutter comes to mind, super aggressive yet cautious and when realized he had growing contempt for IJN escorts, he planned to asked for a rest, but his division commander recognized this and had orders made for new construction after four highly successful patrols.Cutter's predecessor, was over cautious and relieved after one command due to inability to sink anything in a hot area.

Sure, there is no real danger in this sim so some may be super aggressive even to the point of being reckless, but I will say, with full realism on(no external cam, contacts off sometimes) and as escorts get tougher, with all the time you invest in playing just one patrol, let a lone a career, i know some of us(myself included) tend to operate in an aggressive yet cautious manner.

[grislyatoms]

I can't tell you as much as I would like, but I can give you a few hints.

First off, references give the warhead weight, but rarely say anything about the actual charge. I suspect the warhead wt. includes the casing, and perhaps the exploder as well.

As far as the explosives is concerned, I know the US used TNT at first, then adopted Torpex. I believe the IJN used picric acid or something based on it. I don't know much about Hexonite. I wouldn't give too much weight to explosive energy per kilogram. I don't think this correlates well with "effectiveness". Explosives were tested in various ways, and their suitability for a purpose was likely to be decided by a combination of factors. For instance, the detonation velocity, correlates well with the "shattering effect", where hull plates (or whatever) would be broken apart.

I found this list of some explosives on Wiki:
http://en.wikipedia.org/wiki/Relative_effectiveness_factor

Torpex wasn't on the list, but I've read that it was considered about 50% more effective than TNT.

By the way, I should note, some gamers use damage models, where a 100x charge is only does 10x more damage. (I consider this dubious when talking about ship hulls.) The overall model is obviously very important here.


Was reading Wahoo's patrol logs the other day - Mush, for one, much preferred Torpex. He wrote that TNT didn't have the same "whacking" (his term) effect as Torpex. Something to do with the aluminized filler and the length of the detonation pulse/detonation velocity, as you mentioned.

[TorpX]

Yes, they certainly thought Torpex was more powerful. I don't know the details of how it was tested, but I believe the UK conducted tests with charges detonated near scaled down "hull" sections underwater to ascertain it's effectiveness.

In terms of the chemistry, the aluminum is added because it has a high heat of combustion, and is used in other explosives, so it is not unusual. There were safety concerns about Torpex, but the UK used it in bombs, and I think it was shown to be a worthwhile improvement. The books I've read are very vague about just when torpedo warheads started using Torpex, or how heavy a charge they used.

[Rammstein0991]

As an earlier post pointed out DD's=death to a U boot/Fleet Boat. Some would say "Oh but attacking lone merchants is no challenge", and in the game this may be true but you must consider in real life they didnt care if it was challenging or not, all they wanted was to go out, sink some ships, and make it back to their families alive, if this meant sinking unescorted lone merchants or raiding harbors and hitting them at anchor if escorts were absent there, so be it. They were more concerned about surviving to fight the war and get back home than showing how daring they were by hitting heavily escorted convoys.

[Aktungbby]

how well could a sub mask its signature if it sat as close to the bottom as possible in water shallow enough? i understand that a sandy bottom wouldnt echo, but what if its really rocky? and somewhat related, has a submarine ever settled on the bottom to avoid detection?
Belatedly admittingly: From Hitler's Uboat War vol II, at least one Mediterranean U-boat "lay doggo" on the bottom during a depth charge attack. Never works for me in SH's though!:Kaleun_Sleep:

[Aktungbby]

This is a great thread and sincere thanks for everyone who contributed to the information. I read it all in one hit, fascinating

The thing that has crossed my mind more than once is what the submariners were expected to do with their adult urges? 80 days with no women! :D I guess atleast in port it would help the lesser desirable women to pickup a hot sailor date as I cant say I'd have any sort of standards left from 80 days without :arrgh!: Does she have a heartbeat? CHECK! Prepare to dive!

I wonder if it would be possible for people who've been on subs in a navy to talk about these issues in a way that doesnt attract the moderators wrath? From a tactical sense I seriously submit that the lack of sex in young males could have tactical drawbacks to their performance in operations.

The other issue I could see coming out of all this, is say young sailor has his liberty and runs a mock in the pubs, is too drunk to hookup a local woman, gets coerced by a local prostitute and he goes with that, when he manages to stumble his way back to the boat he's now got a sexually transmitted disease that will effect his performance on operations

For some reason it seems never to get discussed in submarine books that I've seen
Obviously, your not subsimming hard enough! :Kaleun_Salivating:

[Aktungbby]

As an earlier post pointed out DD's=death to a U boot/Fleet Boat. Some would say "Oh but attacking lone merchants is no challenge", and in the game this may be true but you must consider in real life they didnt care if it was challenging or not, all they wanted was to go out, sink some ships, and make it back to their families alive, if this meant sinking unescorted lone merchants or raiding harbors and hitting them at anchor if escorts were absent there, so be it. They were more concerned about surviving to fight the war and get back home than showing how daring they were by hitting heavily escorted convoys.
Acquaint yourself with the treatise on the 'OODA loop' by which doctrine we have oriented our combat tactics in the modern age. Originally developed for aircraft combat, it applies to subs as well since, in sense, they are flying in a multi-dimensional element as well. Observe, Orientate, Decide, Act: favors the lone ship attack as the sub is inside the target's OODA loop generally observing first ,stealth and superior speed etc. when attacking the convoy the OODA situation is or rapidly becomes reversed and multiple communicating escorts will have "U" in THEIR OODA loop. Challenges are to be avoided, as in all combat 'equallness' is to be avoided in favor of cold-blooded execution. After the Iraq war, a military commentator noted "we got inside their loop" he was referring to OODA. As U-boat warfare is essentially UNALIGNED warfare (sea guerilla) against a superior enemy, and really with only WWI's technology and a compromised enigma, high-centimetric radar,DFing and sonar have obviated the guerilla's subterfuge and stealth advantage, single vessels ARE the preferred target. :Kaleun_Salute:

[Nuc]

For those interested see my post here:
http://www.subsim.com/radioroom/showthread.php?p=2125585#post2125585

[Platapus]

Hi all,
I'm wondering if someone can tell me a little bit about the warheads used in German and American torpedoes during WWII. Specifically, I'm wondering what the explosive power of Hexanite (the Kriegsmarine explosive of choice) and Torpex (USN) is in joules per kilogram. I'm trying to determine a standard frame of reference for comparing USN and Kreigsmarine torpedoes from this era.

Thanks

http://www.subsim.com/radioroom/showpost.php?p=1268993&postcount=12

We had a discussion about this on this thread. There might be some information useful to you there.

[TorpX]

I often play the S-class boats, and I was wondering about their engine speed options.

We know what we can choose with fleetboat, which have four engines:

1/3 ------------------- one engine
Slow ----------------- two engines
Standard------------- three engines
Full ------------------ four engines
Flank ---------------- four engines + battery

So what would we have with a two engined S-boat? Would most of the engine telegraph orders be meaningless?

[Admiral Halsey]

I often play the S-class boats, and I was wondering about their engine speed options.

We know what we can choose with fleetboat, which have four engines:

1/3 ------------------- one engine
Slow ----------------- two engines
Standard------------- three engines
Full ------------------ four engines
Flank ---------------- four engines + battery

So what would we have with a two engined S-boat? Would most of the engine telegraph orders be meaningless?


I think in the case of the S-Boats the engine RMPs would be lowered.

[Snarf]

http://www.navsea.navy.mil/nswc/carderock/pub/who/sites/bayview.aspx
I'm surprised nobody has made mention of this. After pearl harbor the navy wanted an inland naval facility. This resulted in a naval base at Lake Pend Orielle in Idaho.

[merc4ulfate]

Read em and weep or laugh.

Digital format of the microfilmed patrol reports of the U.S. Fleet boat during World War II beginning in 1923 until the end of the war.

http://www.hnsa.org/doc/subreports.htm

I enjoy reading it straight from the horses mouth.

================================

[scott613]

Hi Folks,

I loaded up the "improved ship physics" mod with the recommended RFB - and while I think it improved the turn rates - does it make the dive happen too fast ? Either crash dive or normal dive seems to happen in well under 30 seconds - that seems a bit too quick to be realistic ? Anyone know what average dive times were on WWII submarines - both crash and normal ?

[Dread Knot]

For a Gato or Tench class boat, 40 to 45 seconds was the norm. Eventually improved crew training and cutting the conning tower with limber holes to enable free-flooding cut this time down to 30-35 seconds.

[scott613]

Thanks for the info - modern boats couldn't even come close to matching those dive times - but - I guess they really don't need to anymore.

[Dread Knot]

Given their massive size that would be difficult for modern boats. But it sounds like submerging is something you really only do once a patrol nowadays. :)

[Sailor Steve]

Either crash dive or normal dive seems to happen in well under 30 seconds?
A "normal" dive involves carefully flooding the ballast tanks to neutral bouyancy and using the planes to control the dive. A crash dive means flooding everything and putting the planes on full down. This is why a crash dive takes the boat so deep - it takes time to blow the tanks to neutral and pull out of a dive like that. A "normal" dive should take a lot longer to get under than a crash dive, possibly twice as long. I'm betting nobody ever timed a normal dive, because nobody cares how long that takes.

[TorpX]

Hi Folks,

I loaded up the "improved ship physics" mod with the recommended RFB - and while I think it improved the turn rates - does it make the dive happen too fast ? Either crash dive or normal dive seems to happen in well under 30 seconds - that seems a bit too quick to be realistic ? Anyone know what average dive times were on WWII submarines - both crash and normal ?

I'm working on the next version of ISP, and may tweak sub diving some. I'm not entirely happy with them either.

Part of the problem is that details of the dives is lacking, and they don't say if they if it took X seconds to reach periscope depth (and level off), or if it took X seconds to reach periscope depth (on their way to 200 ft.). I made the assumption that the times listed were the former, as I don't see crash diving to 200 ft. as a practical course of action, in general.

Since this is a war simulation, I assumed that even 'normal' dives were made on a hasty basis, and started from a condition of 'riding the vents' (where possible), having holes drilled in the superstructure, alert crew, etc.

The game only has 'crash' and 'normal' dives, with no manual control of planes/tanks, or other controls. So options here are limited. If I based 'normal' dive characteristics on peacetime performance, this would likely be a severe handicap for players.

[Joalphski]

A "normal" dive involves carefully flooding the ballast tanks to neutral bouyancy and using the planes to control the dive. A crash dive means flooding everything and putting the planes on full down. This is why a crash dive takes the boat so deep - it takes time to blow the tanks to neutral and pull out of a dive like that. A "normal" dive should take a lot longer to get under than a crash dive, possibly twice as long. I'm betting nobody ever timed a normal dive, because nobody cares how long that takes.

No wonder why my sub keeps diving after I try to crash dive then immediately try to go to periscope depth. Thx for info. My wonder has been answered. :salute:

[nionios]

I would like to ask if the submariners used to rescue the survivors of the ships they had just sunk, in real war of course.Maybe they were obliged to do so?
Also during bad weather or when on high seas do the lookout crew remained on the bridge or the sub remained on surface with only periscope for lookout?

[Aktungbby]

Since you ask in SHIV thread I'll restrict it to the Pacific war: from a previous post:
In May 1942 the Japanese began transferring POWs by sea. Similar to treatment on the Bataan Death March (http://en.wikipedia.org/wiki/Bataan_Death_March), prisoners were often crammed into cargo holds with little air, food or water for journeys that would last weeks. Many died due to asphyxia (http://en.wikipedia.org/wiki/Asphyxia), starvation (http://en.wikipedia.org/wiki/Starvation) or dysentery (http://en.wikipedia.org/wiki/Dysentery). Some POWs became delirious and unresponsive in their environment of heat, humidity and lack of oxygen, food, and water. These unmarked prisoner transports were targeted as enemy ships by Allied submarines (http://en.wikipedia.org/wiki/Submarine) and aircraft.
More than 20,000 Allied POWs died at sea when the transport ships carrying them were attacked by Allied submarines and aircraft. Although Allied headquarters often knew of the presence of POWs through radio interception and code breaking, the ships were sunk because interdiction of critical strategic materials (http://en.wikipedia.org/wiki/Strategic_material) was more important than the deaths of prisoners-of-war Lisbon Maru (http://en.wikipedia.org/wiki/Lisbon_Maru) was carrying 2,000 British POWs from Hong Kong (http://en.wikipedia.org/wiki/Hong_Kong) to Japan in appalling conditions when torpedoed by USS Grouper (http://en.wikipedia.org/wiki/USS_Grouper_(SS-214)) on 1 October 1942. 800 POWs died when the ship sank the following day. Many were shot or otherwise killed by the ship's Japanese guards.
Rakuyo Maru

Rakuyo Maru (http://en.wikipedia.org/wiki/SS_Rakuyo_Maru) was torpedoed 12 September 1944 by USS Sealion (http://en.wikipedia.org/wiki/USS_Sealion_(SS-315)) which later realized the ship carried Allied POWs. Footage of some of the survivors subsequently being picked up by the submarine is available here (http://www.youtube.com/watch?v=QFB4bZUJn6A)
Suez Maru Maru was a 4,645-ton freighter with passenger accom­modation. She sailed on 25 November 1943 with 548 POW (415 British and 133 Dutch) from Ambon (http://en.wikipedia.org/wiki/Ambon,_Maluku) bound for Surabaya (http://en.wikipedia.org/wiki/Surabaya). The POWs were all sick men from the work-camps on the Moluccas and Ambon. Twenty were stretcher cases. On 29 November 1943 the ship was torpedoed by USS Bonefish (http://en.wikipedia.org/wiki/USS_Bonefish) near Kangean Island (http://en.wikipedia.org/wiki/Kangean_Island) east of Madoera Island (http://en.wikipedia.org/wiki/Madura_Island). Most of the POWs drowned in the holds of the ship. Those who escaped from the holds and left the ship were shot by the Japanese. There were no survivors.
Shinyo Maru
Shinyo Maru (http://en.wikipedia.org/wiki/Shinyo_Maru) was attacked (http://en.wikipedia.org/wiki/Shinyo_Maru_Incident) by the submarine USS Paddle (http://en.wikipedia.org/wiki/USS_Paddle) on 7 September 1944. Two torpedo hits sank the ship and killed several hundred US, Dutch (http://en.wikipedia.org/wiki/Netherlands) and Filipino servicemen. Japanese guarding the prisoners opened fire on them while they were trying to abandon ship or swim to the nearby island of Mindanao (http://en.wikipedia.org/wiki/Mindanao). 47 Japanese and 687 Allied POWs were killed. [4] (http://en.wikipedia.org/wiki/Hell_ship#cite_note-4)[5] (http://en.wikipedia.org/wiki/Hell_ship#cite_note-5)
Junyō Maru
The 5,065-ton tramp steamer (http://en.wikipedia.org/wiki/Tramp_steamer) Junyo Maru sailed from Batavia (http://en.wikipedia.org/wiki/Jakarta) (Tandjoeng Priok) on 16 September 1944 with about 4,200 romusha slave labourers and 2,300 POWs aboard. These Dutch POWs included 1,600 from the 10th Battalion camp and 700 from the Kampong Makassar (http://en.wikipedia.org/wiki/Kampong_Makassar) camp. This 23rd transport of POWs from Java was called Java Party 23. Java Party 23 included about 6,500 men bound for Padang on the west coast of Sumatra to work on the Sumatra railway (Mid-Sumatra).
On 18 September 1944 the ship was 15 miles off the west coast of Sumatra near Benkoelen (http://en.wikipedia.org/wiki/Bengkulu) when HMS Tradewind (http://en.wikipedia.org/wiki/HMS_Tradewind) hit her with two torpedoes, one in the bow and one in the stern. About 4,000 romushas and 1,626 POWs died when the ship sank in 20 minutes. About 200 romushas and 674 POWs were rescued by Japanese ships and taken to the Prison in Padang (http://en.wikipedia.org/wiki/Padang), where eight prisoners died. In reality, no skipper of a US submarine could handle the number of POW involved in the above examples of Maru sinkings; and to do so would have endangered the sub crews just from the contagion: typhus and dengue alone, borne by the POWs. In the worst sense, a military decision regarding the 'expendability' of these men was made, and the decision to knowingly sink the vessels was still made. When a ship is sinking, the last man out ahead of the rising water closes the hatch...on those unfortunates still on the ladder; SOP. The ship comes first...always. AND additionally from 2014's nominated Post of the Year; IMHO http://www.subsim.com/radioroom/showpost.php?p=2171794&postcount=8 (http://www.subsim.com/radioroom/showpost.php?p=2171794&postcount=8) :"Let's say in real life in 1942, the ship sinks slowly and there are several hundred Japanese survivors in boats or in the water. Even if you are the most humane of skippers, where would you put them"...

[Threadfin]

No, there was no obligation to rescue survivors, particularly enemy survivors, though some would be hauled aboard as prisoners. However, there were many instances of US boats rescuing allied survivors. For example in July of '43 Permit battle surfaced and sank a Russian trawler with the deck gun and rescued the crew. In January of '44 Guardfish sank the US salvage ship Extractor and rescued the crew of 70. Incidently this was the only confirmed sinking of a US surface ship by US subs.

In maybe the most dramatic example, in September of '44 a wolfpack consisting of Growler, Sealion and Pampanito, was ordered to attack a convoy of 6 ships carrying about 2000 POWS ships near Luzon Strait. Growler attacked first, sinking the frigate Hirado and the destroyer Shikinami. Sealion attacked next, sinking the huge 9,400 ton transport, Raykuyo Maru, and the 8,400 ton transport Nankai Maru. He also hit a tanker in this attack.

The Japanese rescued most of the Japanese in the water, but left the POWs to their fate. The next day Pampanito returned to the area of the attack and began to find survivors, who were shouting 'pick us up please' in English. As a typhoon closed in two more boats, Barb and Queenfish were ordered to join in the rescue.

Enroute to the scene, Barb encountered the carrier Unyo and sank her.

Of the 1,318 prisoners on Rakuyo Maru attacked by Sealion, 159 were rescued by the US boats. Japanese trawlers and frigates rescued 136 men for a total of 295. Of the 900 men on the Kachidoki Maru sunk by Pampanito, 656 men were rescued by a Japanese whale ship, Kibibi Maru.

Then the typhoon prevented further searching and the boats broke off and left the area.

[nionios]

Thank you both for the full response.:up:

[Aktungbby]

Thank you both for the full response.:up:
A footnote to that as the Pampanito is in San Francisco and still one of my favorite destinations...right behind the Liberty Ship Jeremiah O'Brien. "Of the 1,318 POWs on the Rakuyo Maru sunk by Sealion, 159 had been rescued by the four submarines: 73 on Pampanito, 54 on Sealion, and the 32 found by Queenfish and Barb. It was later learned that the Imperial Japanese had rescued 136 for a total of 295 survivors. Of the 900 POWs on the Kachidoki Maru sunk by Pampanito, 656 were rescued by the Imperial Japanese and taken to prison camps in Japan. Over 500 of these men were released by American troops in August, 1945 at the close of the war." http://www.maritime.org/pamphist/patrol3.htm (http://www.maritime.org/pamphist/patrol3.htm)
http://www.maritime.org/img/pampbridge.jpgUSS Pampanito on a clear day.... by San Francisco standards!:hmmm:

[Threadfin]

I don't recall any instances of being surfaced without lookouts posted, perhaps it happened. But I think even if the prospect of being attacked in foul weather were nil, the possibility of collision remained.

If the weather was very bad, such as a typhoon, and he was concerned for the safety of the lookouts or of them being washed overboard, the skipper would choose to run submerged below the rough water as much as possible.

[Aktungbby]

On one U-boat the crew were horrified to discover the lookouts washed over board in Heavy seas In effect the boat had been defenseless without any protection U-106 10/23/1941: A tragic event occurred on U-106 on this date in heavy weather. When the replacement watch opened the conning tower hatch they found that all four men of the previous watch had been lost overboard. [Oberleutnant zur See Werner Grüneberg, Fähnrich zur See Herbert von Bruchhausen, Oberbootsmannmaat Karl Heemann, Matrose Ewald Brühl]:dead:

[svt94]

Sorry if this has been asked before, as i new here. And my grammar sucks.

I keep running into an issue (or maybe not)? Under heavy seas my Fleetboat seems to punch and kinda teater over the waves on the center? sorry kinda hard to explain, i guess. Wish i could post a picture. My net sucks donkey butt. haha.

So my question is: did they punch through the waves kinda like a bullet and teater (SP??) throwing props out of the water, or did they ride the high surf like a larger vessel?

Again. Im sorry. i can't spell or write for the life of me.
Or maybe it is Pabst's? lol Thanks in regards

[TorpX]

In real-life, I think most submarines cut through the waves, instead of riding over them. I believe this is due to their low reserve buoyancy (meaning they are almost heavy enough to sink). However, props did come out of the water at times, and reduce speed. The S-class were known to have poor sea-keeping characteristics, for example.

Don't expect too much from the game. I've noticed the same thing about the waves; the water will push up under the sub, and cause it teeter atop the wave, until it slides off. There have been attempts made to make the waves/effects more realistic, but there are limits to what can be done.

[ikalugin]

What is a normal buoyancy reserve for a surfaced (ww2 era as I assume that this thread is dedicated solely to them) submarine?

[TorpX]

I think it was in the neighborhood of 30%. I believe the S-class would be around 15% and the Narwhals would be over 30, I guess.

[Jolierouge]

The game says "Firing tube x", but how can a Torpedo be "fired"?
Firing something would Need an explosive combustion as far as I am concerned.

Is this the real term used or some dev-thing?

So why not "Launching tube x"?

greetings


Jolie

[Leandros]

The game says "Firing tube x", but how can a Torpedo be "fired"?
Firing something would Need an explosive combustion as far as I am concerned.

Is this the real term used or some dev-thing?

So why not "Launching tube x"?

greetings


Jolie Since you're on it - how can the "tube" be launched (or fired)? The tube is fixed in the boat - the holder (container) of the torpedo. Would not "fire" (or launch) the "torpedo" be the correct term?

Can an "explosion" of compressed air justify the word "fire"?

Fred

[Sailor Steve]

Technically speaking "fire" refers to putting a match to the primer pan, so even a gun isn't really "fired". The Germans use "Los" ("Loose") when launching a torpedo.

American doctrine on the subject is that the torpedo tube is a "gun" and the torpedo a "bullet", and is therefore "fired".
http://maritime.org/doc/fleetsub/tubes/chap1.htm

[Jolierouge]

Ahhhh.......then this is a certain-point-of-view-thing!

Explains a lot.


Okay, thanks....greetings

Jolie

[ssjtoma]

I was always intrigued by the mission to sink the Japanese carrier Shinano!!! It was always a good read!!!!

[wutzthedeal]

This video could be the real life tutorial for SH4! https://www.youtube.com/watch?v=x8DxhS8wpoI

[DeimosFormido]

I've always wondered: what is the purpose of the horizontal steel structure protruding from subs at the aft end?

http://navsource.org/archives/08/193/0819824.jpg

(that thing on the right, horizontal structure made of metal bars)

[ColonelSandersLite]

This video could be the real life tutorial for SH4! https://www.youtube.com/watch?v=x8DxhS8wpoI

I've seen this before but I just now noticed something. At about 2:00 even, there is footage of a ship getting torpedoed. The explosion is on the opposite side of the ship though, so probably a magnetic influence detonation. I don't think I've ever seen footage of that before, or at least never noticed it.

[ETR3(SS)]

I've always wondered: what is the purpose of the horizontal steel structure protruding from subs at the aft end?

http://navsource.org/archives/08/193/0819824.jpg

(that thing on the right, horizontal structure made of metal bars)Welcome aboard Deimos!:salute: Try posting your picture again, can't seem to see it.

[Aktungbby]

DeimosFormido!:Kaleun_Salute:

[Moonlight]

Welcome aboard Deimos!:salute: Try posting your picture again, can't seem to see it.

I'm not surprised it was enormous, this is the picture scaled down.... a lot.

http://i.imgur.com/1uz0jsA.jpg

[ColonelSandersLite]

I'm guessing you mean the propeller guards? The purpose is to protect the propellers.

Been a long while since I looked into them, but my understanding is that they where welded to some boats, bolt on on other boats for removal at sea, and some boats where never even outfitted with them.

[Aktungbby]

Indeed! some had some did not The USS Gato herself never had them. In researching this topic, I came across this interesting vessel...slightly updated. Everything that could go wrong did. USS Grunion https://upload.wikimedia.org/wikipedia/commons/1/11/USS_Grunion%3B0821602.jpg Although there is no absolute certainty the evidence strongly suggests that the Grunion was lost as a result of horrific torpedo performance in the confrontation with the Kano Maru. One torpedo ran low, but despite the magnetic pistol (https://en.wikipedia.org/wiki/Magnetic_pistol) it did not explode; two others bounced off the Kano Maru without exploding. The last one circled back, hitting the periscope (https://en.wikipedia.org/wiki/Periscope) supports on the submerged submarine without exploding.That event, coupled with a jammed rear dive plane (https://en.wikipedia.org/wiki/Diving_plane), triggered a sequence of events that led to loss of depth control. At about 1000 feet the sub would have imploded (https://en.wikipedia.org/wiki/Implosion_(mechanical_process)), then hit the bottom, breaking off about 50 feet of the bow. It then slid 2/3-mile down the side of an extinct volcano, finally coming to rest on a notch on the underwater mountain. https://en.wikipedia.org/wiki/USS_Grunion_(SS-216 (https://en.wikipedia.org/wiki/USS_Grunion_(SS-216))

[ColonelSandersLite]

Also worth mentioning. If you look at pictures of the prop guards, it's very obvious that there are a lot of variations of them.

Compare:
http://www.navsource.org/archives/08/0817808.jpg

Notice that the guard rails are very flat. 2 pairs of cross braces. The lower set is almost horizontal and the top set is heavily angled down. I believe the vertical bar there is a temporary construction support, but I'm not 100% sure on that.




Here's a couple of photos from the wreckage of the grunion:
https://lh3.googleusercontent.com/-Epq__9SpKqk/Rv-pIAxTgHI/AAAAAAAAEFs/7Vpn28u0NMw/s1280-Ic42/1st%252520sight%25252Cport%252520view%25252Cbow%25 2520to%252520stern%25252012.JPEG

https://lh3.googleusercontent.com/-WAWFJbh_I0w/RwDdiwxTg9I/AAAAAAAAEQE/8-c-qAFW1NM/s1280-Ic42/3d%252520sighting%25252C%252520starboard%25252C%25 2520stern%252520to%252520bow%2525203.JPEG
Notice that the cross braces on the topside are nearly horizontal and the bottom braces are angled sharply, the opposite of the above. Also notice that the forward side is angled more than the stern side. Again, the opposite of permit.



Silversides:
https://crashmacduff.files.wordpress.com/2014/03/usn3.jpg
Just completely different, I believe that this is the bolt on setup as evidenced by the next photo.

Silversides without guards:
https://upload.wikimedia.org/wikipedia/commons/8/8f/USS_Silversides%3B0823622.jpg

Silversides Today:
http://www.belairemotel.net/images/stern.jpg
Notice the configuration changed sometime after the above picture was taken. I don't know when.


Barb:
https://crashmacduff.files.wordpress.com/2014/03/usn21.jpg
No guards at all.

Cod today:
http://4.bp.blogspot.com/_sqnjZD8MC7A/SoNCdJSC4TI/AAAAAAAABQ4/nTlbEakhD1A/s1600/040.JPG
Again, completely different.

[TorpX]

Apparently, the Clemson-class DD's had them also.

I couldn't find a good picture of one, but Roscoe's Destroyer Operations book has a drawing of early war Clemsons with them.

[ColonelSandersLite]

Never knew that, but since you bring it up: You can see them clearly on the stern in this photo.

https://upload.wikimedia.org/wikipedia/commons/8/85/USS_Lamson_%28DD-328%29.jpg

Edit:
And here's one with a different POV (different ship)
https://upload.wikimedia.org/wikipedia/commons/c/c0/USS_Goldsborough_%28DD-188%29.jpg

[ShotMagnet]

Elsewhere in this thread it's mentioned that heavy seas can be felt even as deep as 100 feet. My question: since torpedoes of the period commonly ran only a dozen or twenty feet below the surface, how true could they be expected to run in heavy seas?

Could they be launched from much deeper, then assume pre-set depth during their run and therefore mitigate how heavy seas might affect them?


Shot

[Sailor Steve]

They couldn't. Heavy seas were the bane of submarines in WW1 and WW2. Torpedoes could "broach", or break the surface and then dive deep and lose control, or they could break the surface and then explode on hitting the water again. Both Germans and Americans had problems early in the war with torpedoes running too deep on the best of day. Heavy seas made it worse.

According to Peter Pad field's War Beneath The Sea or The Battle of the Atlantic, by Terry Hughes and John Costello (It might be either one - it's been a long time since I read them, and neither's index is helpful in this matter), sometimes in really bad weather an entire convoy would heave to and maintain position, all pointed into the seaway, knowing that no U-boat could attack in those conditions.

As to your second question, also no. The inner torpedo loading door opens inward, and with the outer doors open the pressure at anything deeper than periscope depth could force the inner door open. On top of that, firing on a sonar bearing only was tried by the Americans early in the war and found to be much more difficult than anticipated. So difficult, in fact, that it never worked in actual practice. You would have to take a periscope sighting, and by the time you reached 100 feet or so the solution would be so old you would have pretty much no chance of hitting your target.

So submariners didn't like foul weather any more than the surface sailors did. The only difference was that the sub guys could ride out the storm in relative comfort.

[ShotMagnet]

Thanls, SS. Biding my time and watching YT vids of people playing SH 4 while I await my own copy of the game, I've noticed that a lot of people battle-surface on wounded targets and often elect to administer the coup de grace with the deck gun.

Was this a common practice? I wouldn't think so, but -shock though this will come to some of you- I don't know everything.


Shot

[Sniper297]

According to a lot of the historical books I've read (try your local library non fiction section, maybe you can learn everything) it was pretty common, not only to finish off damaged ships but to sink small ones that weren't worth a torpedo. Sometimes it backfired, I recently read an account of a gun attack on a sampan which turned out to have more and heavier weapons than the sub.

As for the torpedoes, I was in a heavy helicopter anti-submarine squadron, and we had 3 incidents on the same exercise of a Mark 46 torpedo running up the backside of a wave and flying into the air. I didn't personally see these, but the pilots claimed they flew up right through the rotor arc without hitting any of the blades.

[Vox165]

*Bump.* Stumbled on this great thread, for noobs like me looking for RL fleet boat info.

[hunter301]

This question may have already been asked but I don't have time tonight to read thru 5 pages of threads so here it is.....

From what I read in NAVPERS on the fleet type submarine the periscope was slaved to the gyro angle of the torpedo. So when they raised the periscope and gave the command "Bearing-Mark!" and lower the scope to fire how is the bearing transferred to all of the torpedoes when they switch from tube to tube to do a multiple torpedo attack?

[hunter301]

With all this discussion of real sub life and how they work I have to ask...Has anybody seen the movie "Below"?
While I realize it's a horror flick of sorts it is IMHA one of the most visually stunning movies to date of the period date submarines. In this movie you see control aspects of what looks like a Gato or Balao class submarine that you don't usually see. Like when he jumps down into the battery compartment when the hydrogen alarms go off to check the meters. Never seen this before. Or when they go outside and swim inside the baffles of the sub to find the damage causing oil to leak onto the surface giving away their position at time.
One of the scenes that got me was the severity of damage that was being done when the German destroyer was using its grappling hooks to find the sub when it was sitting on the bottom.
Except one of the old black and white episodes of "The Silent Service" on Youtube I have never seen anything else on the use of the grappling hooks.
How often or how many ASW ships had these?
I think they would do more damage than a depth charging.
Why is this not modeled in any of the Silent Hunter games?

[propbeanie]

This question may have already been asked but I don't have time tonight to read thru 5 pages of threads so here it is.....

From what I read in NAVPERS on the fleet type submarine the periscope was slaved to the gyro angle of the torpedo. So when they raised the periscope and gave the command "Bearing-Mark!" and lower the scope to fire how is the bearing transferred to all of the torpedoes when they switch from tube to tube to do a multiple torpedo attack?
With all this discussion of real sub life and how they work I have to ask...Has anybody seen the movie "Below"?
While I realize it's a horror flick of sorts it is IMHA one of the most visually stunning movies to date of the period date submarines. In this movie you see control aspects of what looks like a Gato or Balao class submarine that you don't usually see. Like when he jumps down into the battery compartment when the hydrogen alarms go off to check the meters. Never seen this before. Or when they go outside and swim inside the baffles of the sub to find the damage causing oil to leak onto the surface giving away their position at time.
One of the scenes that got me was the severity of damage that was being done when the German destroyer was using its grappling hooks to find the sub when it was sitting on the bottom.
Except one of the old black and white episodes of "The Silent Service" on Youtube I have never seen anything else on the use of the grappling hooks.
How often or how many ASW ships had these?
I think they would do more damage than a depth charging.
Why is this not modeled in any of the Silent Hunter games?
I am by no means, an expert, but I did stay at Holiday Inn Express last week... Gyro angle is determined by the solution of the targeting problem with the use of the TDC (Torpedo Data Computer) (https://en.wikipedia.org/wiki/Torpedo_Data_Computer), an electro-mechanical computer, like relay logic. That data was sent to the torpedo in the tube. It could also be put in "manually" through the computer for corrections or alterations. The inner torpedo tube door (breech) had an adjustable "stop" that would put the torpedo in the proper position so that the mechanisms to manipulate the torpedoes settings would fit in properly. (If you really want to get into the details of it all, I point you at Chapter 3 of 21-Inch Submerged Torpedo Tubes (https://maritime.org/doc/fleetsub/tubes/chap3.htm) on the Maritime dot Org site, home of the Pampanito.) The skipper might say "Ready all torpedoes for firing" or "Ready tubes 1 and 2 forward. Better get number 9 & 10 ready aft, just in case." While you had the skipper & executive "targeting" with the scope, there would be at least one "team" working on the solution on paper, parallel with what the TDC would do. They might even use a "banjo" (https://maritime.org/doc/banjo/index.htm) to help them figure things out. They would (usually) double-check themselves that way, time permitting, before firing. :salute:

As for the use of a hook, I know of only one documented story, and they aren't even sure about that, since the sub was submerged, and were only going by sound. I would imagine that "hooking" a sub stood a chance of damaging the hook-dragging vessel also. Trying to hook a sub, and they accidentally hook a hulk wreck, partially sunken into the bottom by sediment? Might tear part of dragging vessel off, or maybe pull their stern under, while everyone onboard gets thrown forward by the near-sudden stop... parts of the cable winch go flying as it's destroyed? One reason you won't see it in the game is because of the games engine. There is no allowance for "attached" vehicles. You can have objects "riding" on other objects, but there is no "cable" in the game... :salute:

[hunter301]

As for the use of a hook, I know of only one documented story, and they aren't even sure about that, since the sub was submerged, and were only going by sound. I would imagine that "hooking" a sub stood a chance of damaging the hook-dragging vessel also. Trying to hook a sub, and they accidentally hook a hulk wreck, partially sunken into the bottom by sediment? Might tear part of dragging vessel off, or maybe pull their stern under, while everyone onboard gets thrown forward by the near-sudden stop... parts of the cable winch go flying as it's destroyed? One reason you won't see it in the game is because of the games engine. There is no allowance for "attached" vehicles. You can have objects "riding" on other objects, but there is no "cable" in the game... :salute:

In the movie he is looking at the ONI recognition manual when he says the ship that's attacking them has grapplers. While I'm waiting now for copies of the original ONI manuals to arrive https://www.amazon.com/gp/product/1940453240/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
does anybody else know if they ever listed these as part of their gear?
Nothing relative just curious.

[propbeanie]

Here's an online link from that same maritime dot org site: https://maritime.org/doc/id/index.htm

[Sniper297]

I've read several historical books that mention a sub lying on the bottom hearing the sound of cables dragging across overhead, so although it wasn't done often it was done. Not trying to catch the sub like a fish and haul it out of the water, the problem was trying to locate it when it's lying doggo with motors stopped - sonar bottom echos make it real difficult to pick a confirmed contact out of all the returns coming from the bottom itself.

Speaking of sonar, we've noted in game that the IJN escorts seem to be programmed to be deaf to the sub's sonar and fathometer. In Admiral Lockwood's book SINK 'EM ALL he mentions that sub skippers were finding out as early as the summer of 1942 that a single ping was extremely unlikely to be heard by any nearby destroyers, so they frequently used single pings to confirm range to a target throughout the war.

So there's some real life fact behind it, I'm going to start pinging more often. :ping: